Magnetic field enhancement device

Abstract

This application relates to a magnetic field enhancement device. A first electrode layer is disposed on a first surface. A second electrode layer is disposed on the first surface and located in a first capacitor region, and the second electrode layer is spaced apart from a portion of the first electrode layer located in the first capacitor region. A third electrode layer is disposed on the first surface and located in a second capacitor region, and the third electrode layer is spaced apart from a portion of the first electrode layer located in the second capacitor region. One end of a first resonant capacitor is electrically connected to the second electrode layer, and the other end of the first resonant capacitor is electrically connected to a portion of the first electrode layer located in the first capacitor region. The second electrode layers of adjacent two magnetic field enhancement components are connected to the portion of the first electrode layer located in the first capacitor region. One end of a second resonant capacitor is electrically connected to the third electrode layer, and the other end of the second resonant capacitor is electrically connected to a portion of the first electrode layer located in the second capacitor region. The third electrode layers of adjacent two magnetic field enhancement components are connected to the portion of the first electrode layer located in the second capacitor region.

Description

Technical Field

[0001] This application relates to the field of magnetic resonance imaging technology, and particularly to a magnetic field enhancement device. Background Art

[0002] MRI (Magnetic Resonance Imaging) is a non-invasive detection method and an important basic diagnostic technology in the fields of medicine, biology, and neuroscience. The signal intensity transmitted by traditional MRI devices mainly depends on the intensity of the static magnetic field B0. Using high magnetic field or even ultra-high magnetic field systems can improve the signal-to-noise ratio, resolution, and shorten the scanning time of images. However, the increase in the static magnetic field intensity brings the following three problems: 1) The non-uniformity of the radio frequency (RF) field increases, and the tuning difficulty increases; 2) The heat generation of human tissues increases, bringing potential safety hazards, and patients are also prone to adverse reactions such as dizziness and vomiting; 3) The purchase cost increases significantly, which is a burden for most small-scale hospitals. Therefore, how to obtain high imaging quality with as small a static magnetic field intensity as possible has become a crucial issue in MRI technology.

[0003] The emergence of metamaterials provides a novel and more effective method for improving the imaging quality and efficiency of MRI. Metamaterials have many special properties that natural materials do not possess. Through the interaction between electromagnetic waves and the metal or dielectric elements of metamaterials and the coupling effect between the elements, the control of the propagation path of electromagnetic waves and the distribution of electromagnetic field strength can be achieved. Among them, the specific working principle is to utilize the electromagnetic resonance in the structure formed by metamaterials to realize the adjustment of electromagnetic parameters such as anisotropy and gradient distribution. Moreover, through the design of parameters such as the geometric size, shape, and dielectric constant of metamaterials, the resonance enhancement at different frequency points can be achieved.

[0004] Traditional magnetic field enhancement components include a dielectric plate and a first electrode and a second electrode located on the front and back of the dielectric plate respectively. The positive projection of the second electrode on the dielectric plate is located at both ends of the positive projection of the first electrode on the dielectric plate to form a parallel plate capacitor.

[0005] In the structure of traditional magnetic field enhancement components, the parallel plate capacitors formed are all located on the transmission line formed by strip electrodes. The structure formed by connecting multiple traditional magnetic field enhancement components, after being equivalent to a circuit, has a parallel relationship of multiple parallel plate capacitors. The equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components is close to the sum of the capacitances of multiple parallel plate capacitors. Since capacitance is inversely proportional to frequency, in high-field or ultra-high-field MRI systems (3T and above), as the frequency increases, the equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components becomes smaller. When the equivalent capacitance becomes smaller, the capacitances of multiple parallel plate capacitors also need to be correspondingly smaller. Since the equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components is close to the sum of the capacitances of multiple parallel plate capacitors, it results in the need for very small capacitance values for multiple parallel plate capacitors.

[0006] Therefore, if the capacitance values of multiple parallel plate capacitors are too small, the resonant frequency of the structure formed by connecting multiple traditional magnetic field enhancement components will fluctuate greatly, resulting in poor stability of the resonant frequency. Summary of the Invention

[0007] Based on this, in view of the above problems, it is necessary to provide a magnetic field enhancement device.

[0008] The present application provides a magnetic field enhancement device. The magnetic field enhancement device includes a plurality of magnetic field enhancement components. Each magnetic field enhancement component includes a first dielectric layer, a first electrode layer, a second electrode layer, and a third electrode layer. The first dielectric layer has a first end and a second end disposed opposite to each other. The first dielectric layer further has a first surface that extends from the first end to the second end.

[0009] In the direction from the first end to the second end, the first surface includes a first capacitance region, a conduction region, and a second capacitance region. The conduction region is located between the first capacitance region and the second capacitance region. The first capacitance region is close to the first end. The second capacitance region is close to the second end.

[0010] The first electrode layer is disposed on the first surface. The first electrode layer extends from the first end to the second end. Both ends of the first electrode layer extend towards the first capacitance region and the second capacitance region respectively. The second electrode layer is disposed on the first surface. The second electrode layer is located in the first capacitance region. The second electrode layer is spaced apart from the portion of the first electrode layer located in the first capacitance region.

[0011] The third electrode layer is disposed on the first surface. The third electrode layer is located in the second capacitance region. The third electrode layer is spaced apart from the portion of the first electrode layer located in the second capacitance region.

[0012] Each of the magnetic field enhancement components extends from the first end to the second end. The plurality of magnetic field enhancement components are arranged at intervals and enclose a magnetic field enhancement space. The magnetic field enhancement space is used to place the measured part, thereby enhancing the magnetic field of the measured part.

[0013] The magnetic field enhancement device further includes a plurality of first resonant capacitors. The plurality of first resonant capacitors are arranged close to the first end. One first resonant capacitor is correspondingly arranged with one magnetic field enhancement component. One end of each first resonant capacitor is electrically connected to the second electrode layer. The other end of each first resonant capacitor is electrically connected to the part of the first electrode layer located in the first capacitor region. The second electrode layers of two adjacent magnetic field enhancement components are connected to the part of the first electrode layer located in the first capacitor region. That is, among two adjacent magnetic field enhancement components, the second electrode layer of one magnetic field enhancement component is connected to the part of the first electrode layer of the other magnetic field enhancement component located in the first capacitor region. On the side of the first end, the plurality of magnetic field enhancement components are connected through the second electrode layer in each magnetic field enhancement component and the part of the first electrode layer located in the first capacitor region.

[0014] When the magnetic field enhancement device is arranged in a magnetic field environment, an induced current will be generated. On the side of the first end, the induced current will sequentially pass through the second electrode layer, both ends of the first resonant capacitor, the part of the first electrode layer located in the first capacitor region, the second electrode layer of an adjacent magnetic field enhancement component, both ends of the first resonant capacitor, the part of the first electrode layer located in the first capacitor region, etc. When equivalent to a circuit diagram, the plurality of first resonant capacitors are connected in series one by one in sequence.

[0015] The magnetic field enhancement device further includes a plurality of second resonant capacitors. The plurality of second resonant capacitors are arranged close to the second end. One second resonant capacitor is correspondingly arranged with one magnetic field enhancement component. One end of each second resonant capacitor is electrically connected to the third electrode layer. The other end of each second resonant capacitor is electrically connected to the part of the first electrode layer located in the second capacitor region. The third electrode layers of two adjacent magnetic field enhancement components are connected to the part of the first electrode layer located in the second capacitor region. That is, among two adjacent magnetic field enhancement components, the third electrode layer of one magnetic field enhancement component is connected to the part of the first electrode layer of the other magnetic field enhancement component located in the second capacitor region. On the side of the second end, the plurality of magnetic field enhancement components are connected through the third electrode layer in each magnetic field enhancement component and the part of the first electrode layer located in the second capacitor region.

[0016] When the magnetic field enhancement device is disposed in a magnetic field environment, an induced current will be generated. On one side of the second end, the induced current will sequentially pass through the third electrode layer, both ends of the second resonant capacitor, the portion of the first electrode layer located in the second capacitor region, the third electrode layer of the adjacent magnetic field enhancement component, both ends of the second resonant capacitor, the portion of the first electrode layer located in the second capacitor region, etc. When equivalent to a circuit diagram, the multiple second resonant capacitors are connected in series one by one in sequence.

[0017] The first electrode layer, the second electrode layer, and the third electrode layer are all disposed on the first surface. The first electrode layer, the second electrode layer, and the third electrode layer are arranged on the same surface, and no parallel plate capacitor is formed between them. The first electrode layer, the second electrode layer, and the third electrode layer are all spaced apart and not connected to each other. In the first capacitor region, the second electrode layer and the first electrode layer are spaced apart on the same surface. Both ends of the first resonant capacitor are electrically connected to the second electrode layer and the first electrode layer respectively. In the second capacitor region, both ends of the second resonant capacitor are electrically connected to the third electrode layer and the first electrode layer respectively.

[0018] When the multiple magnetic field enhancement components are connected and placed in a magnetic field environment, the multiple first resonant capacitors are connected in series one by one in sequence. The multiple second resonant capacitors are connected in series one by one in sequence. When the operating frequency of a high-field or ultra-high-field MRI system (3T and above) is the same as the resonant frequency of the magnetic field enhancement device, the magnetic field enhancement device can enhance the magnetic field.

[0019] Since capacitance is inversely proportional to frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency is relatively large, and the equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components needs to be relatively small. However, the series connection of the multiple first resonant capacitors will make the equivalent capacitance formed by the multiple first resonant capacitors smaller. The series connection of the multiple second resonant capacitors will make the equivalent capacitance formed by the multiple second resonant capacitors smaller. When distributing the capacitance value in the resonant frequency of the magnetic field enhancement device to the multiple first resonant capacitors and the multiple second resonant capacitors, the capacitance values of the multiple first resonant capacitors and the multiple second resonant capacitors can adopt large capacitance values, avoiding the use of capacitors with too small capacitance values. Using capacitors with large capacitance values makes the resonant frequency fluctuation of the structure formed by the magnetic field enhancement device smaller, improves the stability of the resonant frequency, and is more suitable for high-field MRI. Description of the Drawings

[0020] To more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 Explosion structure schematic diagram of the magnetic field enhancement component in an embodiment provided by the present application;

[0022] Figure 2 Structure schematic diagram of the magnetic field enhancement device in an embodiment provided by the present application;

[0023] Figure 3 Top view of the magnetic field enhancement component in an embodiment provided by the present application;

[0024] Figure 4 Equivalent circuit diagram of the magnetic field enhancement device in an embodiment provided by the present application;

[0025] Figure 5 Top view of the magnetic field enhancement component in an embodiment provided by the present application;

[0026] Figure 6 Structure schematic diagram of the magnetic field enhancement device in an embodiment provided by the present application;

[0027] Figure 7 Top view of the magnetic field enhancement component in an embodiment provided by the present application;

[0028] Figure 8 Top view of the magnetic field enhancement component in an embodiment provided by the present application;

[0029] Figure 9 Top view of the magnetic field enhancement component in an embodiment provided by the present application;

[0030] Figure 10 Structure schematic diagram of the magnetic field enhancement device in an embodiment provided by the present application;

[0031] Figure 11 Structure schematic diagram of the magnetic field enhancement device in an embodiment provided by the present application;

[0032] Figure 12 Provided by the present application Figure 11 Connection structure schematic diagram of the magnetic field enhancement component, the third conductive structure, the fourth conductive structure, the first resonant capacitor, and the second resonant capacitor in it;

[0033] Figure 13The top view of the magnetic field enhancement component in an embodiment provided by this application;

[0034] Figure 14 The side view of the magnetic field enhancement component in an embodiment provided by this application;

[0035] Figure 15 The side view of the first end of the magnetic field enhancement component in an embodiment provided by this application;

[0036] Figure 16 The side view of the second end of the magnetic field enhancement component in an embodiment provided by this application;

[0037] Figure 17 The side view of the magnetic field enhancement component in an embodiment provided by this application;

[0038] Figure 18 The structural schematic diagram of the magnetic field enhancement device in an embodiment provided by this application;

[0039] Figure 19 The structural schematic diagram of the magnetic field enhancement device in an embodiment provided by this application;

[0040] Figure 20 The comparison diagram of the resonance frequencies of the magnetic field enhancement device and the traditional structure in an embodiment provided by this application;

[0041] Figure 21 The magnetic field distribution of the magnetic field enhancement device in an embodiment provided by this application.

[0042] Explanation of reference numerals:

[0043] Magnetic field enhancement device 20, magnetic field enhancement component 10, first dielectric layer 100, first electrode layer 110, second electrode layer 120, third electrode layer 130, first end 103, second end 104, first surface 101, second surface 102, first capacitance region 11, conduction region 13, second capacitance region 12, magnetic field enhancement space 105, first resonance capacitor 911, second resonance capacitor 921, first conductive structure 519, second conductive structure 529, fifth diode 461, sixth diode 462, fifth external capacitor 445, first depletion-type MOS transistor 231, second depletion-type MOS transistor 232, third conductive structure 539, fourth conductive structure 549, first inductor 241, third diode 213, fourth diode 214, cylindrical support structure 50, third end 51, fourth end 53, inner surface 521, outer surface 522, detection space 509, fourth electrode layer 140, first structural capacitor 151, second structural capacitor 152, first external capacitor 440, first diode 431, second diode 432. Detailed implementation manners

[0044] For the convenience of understanding the present application, the present application will be described more comprehensively below with reference to the relevant accompanying drawings. Embodiments of the present application are given in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, these embodiments are provided to make the disclosure of the present application more thorough and comprehensive.

[0045] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0046] It can be understood that the terms "first", "second", etc. used in this application can be used herein to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from another element. For example, without departing from the scope of this application, the first resistor can be called the second resistor, and similarly, the second resistor can be called the first resistor. Both the first resistor and the second resistor are resistors, but they are not the same resistor.

[0047] It can be understood that for the "connection" in the following embodiments, if there is an electrical signal or data transfer between the connected circuits, modules, units, etc., it should be understood as "electrical connection", "communication connection", etc.

[0048] As used herein, the singular forms "a", "an" and "the" may also include the plural forms unless the context clearly dictates otherwise. It should also be understood that the terms "comprise / include" or "have" etc. specify the presence of the stated features, wholes, steps, operations, components, parts or combinations thereof, but do not preclude the presence or addition of one or more other features, wholes, steps, operations, components, parts or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the related listed items.

[0049] Please refer to Figure 1 , the present application provides a magnetic field enhancement device 20. The magnetic field enhancement device 20 includes a plurality of magnetic field enhancement components 10. Each magnetic field enhancement component 10 includes a first dielectric layer 100, a first electrode layer 110, a second electrode layer 120, and a third electrode layer 130. The first dielectric layer 100 has a first end 103 and a second end 104 which are oppositely arranged. The first dielectric layer 100 also has a first surface 101 which extends from the first end 103 to the second end 104.

[0050] In the direction from the first end 103 to the second end 104, the first surface 101 includes a first capacitor region 11, a conduction region 13, and a second capacitor region 12. The conduction region 13 is located between the first capacitor region 11 and the second capacitor region 12. The first capacitor region 11 is close to the first end 103. The second capacitor region 12 is close to the second end 104.

[0051] The first electrode layer 110 is disposed on the first surface 101. The first electrode layer 110 extends from the first end 103 to the second end 104. Both ends of the first electrode layer 110 extend towards the first capacitor region 11 and the second capacitor region 12 respectively. The second electrode layer 120 is disposed on the first surface 101. The second electrode layer 120 is located in the first capacitor region 11. The second electrode layer 120 is spaced apart from the portion of the first electrode layer 110 located in the first capacitor region 11.

[0052] The third electrode layer 130 is disposed on the first surface 101. The third electrode layer 130 is located in the second capacitor region 12. The third electrode layer 130 is spaced apart from the portion of the first electrode layer 110 located in the second capacitor region 12.

[0053] Please refer to Figure 2 , each of the magnetic field enhancement components 10 extends from the first end 103 to the second end 104. The plurality of magnetic field enhancement components 10 are spaced apart and enclose to form a magnetic field enhancement space 105. The magnetic field enhancement space 105 is used to place the measured part, thereby enhancing the magnetic field of the measured part.

[0054] Please refer to Figure 3, the magnetic field enhancement device 20 further includes a plurality of first resonant capacitors 911. The plurality of first resonant capacitors 911 are disposed close to the first end 103. One of the first resonant capacitors 911 is correspondingly disposed with one of the magnetic field enhancement components 10. One end of each of the first resonant capacitors 911 is electrically connected to the second electrode layer 120. The other end of each of the first resonant capacitors 911 is electrically connected to the portion of the first electrode layer 110 located in the first capacitor region 11. The second electrode layer 120 of two adjacent magnetic field enhancement components 10 is connected to the portion of the first electrode layer 110 located in the first capacitor region 11. That is, in two adjacent magnetic field enhancement components 10, the second electrode layer 120 of one of the magnetic field enhancement components 10 is connected to the portion of the first electrode layer 110 of the other magnetic field enhancement component 10 located in the first capacitor region 11. On one side of the first end 103, the plurality of magnetic field enhancement components 10 are connected through the second electrode layer 120 in each of the magnetic field enhancement components 10 and the portion of the first electrode layer 110 located in the first capacitor region 11.

[0055] When the magnetic field enhancement device 20 is disposed in a magnetic field environment, an induced current will be generated. On one side of the first end 103, the induced current will sequentially pass through the second electrode layer 120, both ends of the first resonant capacitor 911, the portion of the first electrode layer 110 located in the first capacitor region 11, the second electrode layer 120 of the adjacent magnetic field enhancement component 10, both ends of the first resonant capacitor 911, the portion of the first electrode layer 110 located in the first capacitor region 11, etc. Please refer to Figure 4 , when equivalent to a circuit diagram, the plurality of first resonant capacitors 911 are connected in series one by one in sequence.

[0056] The magnetic field enhancement device 20 further includes a plurality of second resonant capacitors 921. The plurality of second resonant capacitors 921 are arranged close to the second end 104. One of the second resonant capacitors 921 is arranged corresponding to one of the magnetic field enhancement components 10. One end of each second resonant capacitor 921 is electrically connected to the third electrode layer 130, and the other end of each second resonant capacitor 921 is electrically connected to the portion of the first electrode layer 110 located in the second capacitor region 12. The third electrode layers 130 of two adjacent magnetic field enhancement components 10 are connected to the portion of the first electrode layer 110 located in the second capacitor region 12. That is, among two adjacent magnetic field enhancement components 10, the third electrode layer 130 of one magnetic field enhancement component 10 is connected to the portion of the first electrode layer 110 of the other magnetic field enhancement component 10 located in the second capacitor region 12. On one side of the second end 104, the plurality of magnetic field enhancement components 10 are connected through the third electrode layer 130 in each magnetic field enhancement component 10 and the portion of the first electrode layer 110 located in the second capacitor region 12.

[0057] When the magnetic field enhancement device 20 is arranged in a magnetic field environment, an induced current will be generated. On one side of the second end 104, the induced current will sequentially pass through the third electrode layer 130, both ends of the second resonant capacitor 921, the portion of the first electrode layer 110 located in the second capacitor region 12, the third electrode layer 130 of an adjacent magnetic field enhancement component 10, both ends of the second resonant capacitor 921, the portion of the first electrode layer 110 located in the second capacitor region 12, etc. Please refer to Figure 4 , when equivalent to a circuit diagram, the plurality of second resonant capacitors 921 are connected in series one by one in sequence.

[0058] The first electrode layer 110, the second electrode layer 120, and the third electrode layer 130 are all arranged on the first surface 101. The first electrode layer 110, the second electrode layer 120, and the third electrode layer 130 are arranged on the same surface and do not form a parallel plate capacitor with each other. The first electrode layer 110, the second electrode layer 120, and the third electrode layer 130 are all arranged at intervals and are not connected to each other. In the first capacitor region 11, the second electrode layer 120 and the first electrode layer 110 are arranged at intervals on the same surface. Both ends of the first resonant capacitor 911 are electrically connected to the second electrode layer 120 and the first electrode layer 110 respectively. In the second capacitor region 12, both ends of the second resonant capacitor 921 are electrically connected to the third electrode layer 130 and the first electrode layer 110 respectively.

[0059] When the multiple magnetic field enhancement components 10 are connected and placed in a magnetic field environment, the multiple first resonant capacitors 911 are connected in series one by one in sequence. The multiple second resonant capacitors 921 are connected in series one by one in sequence. When the operating frequency of a high-field or ultra-high-field MRI system (3T and above) is the same as the resonant frequency of the magnetic field enhancement device 20, the magnetic field enhancement device 20 can enhance the magnetic field.

[0060] Since capacitance is inversely proportional to frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency is relatively large, which requires the equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components to be relatively small. However, the series connection of the multiple first resonant capacitors 911 will make the equivalent capacitance formed by the multiple first resonant capacitors 911 smaller. The series connection of the multiple second resonant capacitors 921 will make the equivalent capacitance formed by the multiple second resonant capacitors 921 smaller. When the capacitance values in the resonant frequency of the magnetic field enhancement device 20 are allocated to the multiple first resonant capacitors 911 and the multiple second resonant capacitors 921, the capacitance values of the multiple first resonant capacitors 911 and the multiple second resonant capacitors 921 can adopt large capacitance values, avoiding the use of capacitors with too small capacitance values. Using capacitors with large capacitance values makes the resonant frequency of the magnetic field enhancement device 20 fluctuate less, improves the stability of the resonant frequency, and is more suitable for high-field MRI.

[0061] The magnetic field enhancement device 20 is a high-frequency MRI image enhancement metasurface device. The high-frequency MRI image enhancement metasurface device enables the metasurface under high-frequency operation to have a relatively large capacitance value, avoiding the use of capacitors with too small capacitance values. The high-frequency MRI image enhancement metasurface device, by avoiding the use of capacitors with too small capacitance values, increases the tunability and resonant frequency stability of the high-frequency MRI image enhancement metasurface device under high-frequency operating conditions.

[0062] The high-frequency MRI image enhancement metasurface device, by using capacitors with large capacitance values, makes the resonant frequency of the high-frequency MRI image enhancement metasurface device fluctuate less. The high-frequency MRI image enhancement metasurface device, by using capacitors with large capacitance values, improves the stability of the resonant frequency of the high-frequency MRI image enhancement metasurface device and is more suitable for high-field MRI.

[0063] In one embodiment, the materials of the first electrode layer 110, the second electrode layer 120, and the third electrode layer 130 can be non-magnetic metals such as copper, silver, and gold. The material of the first dielectric layer 100 can be a material with a flame retardant rating of FR4, a high-temperature thermoplastic resin such as polyphenylene oxide (PPE), or a Rogers 4003C material, etc.

[0064] In one embodiment, the materials of the first electrode layer 110, the second electrode layer 120, and the third electrode layer 130 are the same, all being copper foils.

[0065] Please refer to Figure 5 , in one embodiment, in the first capacitor region 11, the first resonant capacitor 911 is disposed on the first surface 101. In the second capacitor region 12, the second resonant capacitor 921 is disposed on the first surface 101.

[0066] In the first capacitor region 11, the second electrode layer 120 is spaced apart from the first electrode layer 110. Opposite ports of the second electrode layer 120 and the first electrode layer 110 form a first gap, exposing the first surface 101. The first resonant capacitor 911 is disposed on the first surface 101 in the first gap. In the second capacitor region 12, the third electrode 130 is spaced apart from the first electrode layer 110. Opposite ports of the third electrode 130 and the first electrode layer 110 form a second gap, exposing the first surface 101. The second resonant capacitor 921 is disposed on the first surface 101 in the second gap.

[0067] The first resonant capacitor 911 is disposed on the first surface 101 in the first gap. Two ends of the first resonant capacitor 911 can be electrically connected to the second electrode layer 120 and the first electrode layer 110 using fewer leads. The second resonant capacitor 921 is disposed on the first surface 101 in the second gap. Two ends of the second resonant capacitor 921 can be electrically connected to the third electrode 130 and the first electrode layer 110 using fewer leads. Since there are fewer leads connecting the capacitors, excessive inductance introduced by the leads can be avoided, which may affect the resonant frequency of the magnetic field enhancement device 20, resulting in a smaller fluctuation in the resonant frequency of the magnetic field enhancement device 20, improving the stability of the resonant frequency, and making it more suitable for high-field MRI.

[0068] In one embodiment, the magnetic field formed by the first electrode layer 110 located in the conduction region 13 is the main magnetic field of the magnetic field enhancement device 20. The space surrounded by the first electrode layer 110 located in the conduction region 13 is the main magnetic field enhancement space. The first resonant capacitor 911 and the second resonant capacitor 921 are symmetric with respect to the first electrode layer 110 in the conduction region 13. The first resonant capacitor 911 and the second resonant capacitor 921 are symmetrically arranged at the first end 103 and the second end 104 respectively, so that the magnetic field formed by the magnetic field enhancement device 20 is more uniform and symmetric, which is more conducive to detecting the detection site and improving the image quality of the MRI device. The first resonant capacitor 911 and the second resonant capacitor 921 are symmetrically arranged at the first end 103 and the second end 104 respectively, so that the first resonant capacitor 911 and the second resonant capacitor 921 are far away from the magnetic field enhancement space 105, which can avoid the electric field generated by the capacitor from damaging the detection site.

[0069] Please refer to Figure 6 , in one embodiment, the magnetic field enhancement device 20 further includes a plurality of first conductive structures 519 and a plurality of second conductive structures 529. The plurality of first conductive structures 519 are arranged close to the first end 103. Each of the first conductive structures 519 is arranged between two adjacent magnetic field enhancement components 10. Both ends of each of the first conductive structures 519 are respectively connected to the portions of the second electrode layer 120 and the first electrode layer 110 of two adjacent magnetic field enhancement components 10 located in the first capacitor region 11. That is, one end of a first conductive structure 519 is connected to the second electrode layer 120 of a magnetic field enhancement component 10. The other end of a first conductive structure 519 is connected to the portion of the first electrode layer 110 of the adjacent magnetic field enhancement component 10 located in the first capacitor region 11.

[0070] On one side of the first end 103, the plurality of magnetic field enhancement components 10 are sequentially connected through the plurality of first conductive structures 519. The induced current will sequentially pass through the second electrode layer 120, both ends of the first resonant capacitor 911, the portion of the first electrode layer 110 located in the first capacitor region 11, the first conductive structure 519, the second electrode layer 120 of the adjacent magnetic field enhancement component 10, both ends of the first resonant capacitor 911, the portion of the first electrode layer 110 located in the first capacitor region 11, the first conductive structure 519, etc. When equivalent to a circuit diagram, the plurality of first resonant capacitors 911 are sequentially connected in series one by one through the plurality of first conductive structures 519.

[0071] The multiple second conductive structures 529 are disposed near the second end 104. Each of the second conductive structures 529 is disposed between two adjacent magnetic field enhancement components 10. Two ends of each of the second conductive structures 529 are respectively connected to portions of the third electrode layer 130 and the first electrode layer 110 of two adjacent magnetic field enhancement components 10 that are located in the second capacitance region 12. That is, one end of a second conductive structure 529 is connected to the third electrode layer 130 of a magnetic field enhancement component 10, and the other end of the second conductive structure 529 is connected to a portion of the first electrode layer 110 of an adjacent magnetic field enhancement component 10 that is located in the second capacitance region 12.

[0072] On one side of the second end 104, the multiple magnetic field enhancement components 10 are sequentially connected through the multiple second conductive structures 529. The induced current will sequentially pass through the third electrode layer 130, both ends of the second resonant capacitor 921, a portion of the first electrode layer 110 that is located in the second capacitance region 12, the second conductive structure 529, the third electrode layer 130 of an adjacent magnetic field enhancement component 10, both ends of the second resonant capacitor 921, a portion of the first electrode layer 110 that is located in the second capacitance region 12, the second conductive structure 529, etc. When equivalent to a circuit diagram, the multiple second resonant capacitors 921 are connected in series one by one through the multiple second conductive structures 529.

[0073] In one embodiment, the first conductive structure 519 and the second conductive structure 529 have a conductive function. The materials of the first conductive structure 519 and the second conductive structure 529 can be made of metal materials such as gold, silver, and copper.

[0074] Please refer to Figure 7 , in one embodiment, the magnetic field enhancement device 20 further includes a fifth diode 461, a sixth diode 462, and a fifth external capacitor 445. An anode of the fifth diode 461 is electrically connected to the second electrode layer 120. A cathode of the sixth diode 462 is electrically connected to the second electrode layer 120. One end of the fifth external capacitor 445 is electrically connected to the first electrode layer 110 that is located in the first capacitance region 11, and the other end of the fifth external capacitor 445 is electrically connected to a cathode of the fifth diode 461 and an anode of the sixth diode 462 respectively.

[0075] In an MRI system, to enhance the magnetic field intensity of the human body feedback signal in the RF reception stage. In the RF transmission stage of the MRI system, the magnetic field energy in the transmission stage is more than 1000 times that in the reception stage. The induced voltage in the transmission stage is between several tens of volts and several hundreds of volts. The induced voltage in the reception stage is less than 1V.

[0076] The fifth diode 461 and the sixth diode 462 are connected in reverse parallel. During the radio frequency (RF) transmission stage, the RF coil emits an RF transmission signal, and the magnetic field has a relatively large field strength. The induced voltage generated by the magnetic field enhancement component 10 is relatively large. The voltages applied across the fifth diode 461 and the sixth diode 462 alternate in polarity. When the applied voltage exceeds the turn-on voltages of the fifth diode 461 and the sixth diode 462, the fifth diode 461 and the sixth diode 462 conduct. The fifth external capacitor 445 is connected in parallel with the first resonant capacitor 911, resulting in parallel resonance and making the circuit in a high-impedance state. During the RF signal transmission stage, there is almost no current flowing between two adjacent magnetic field enhancement components 10. The first resonant capacitor 911 is disconnected from two adjacent magnetic field enhancement components 10 respectively, and no current passes through, being in a detuned state. The magnetic field generated by the magnetic field enhancement device 20 weakens, thereby reducing the influence of the magnetic field enhancement device 20 on the magnetic field during the RF signal transmission stage, reducing the artifacts in the detected image, and improving the clarity of the detected image.

[0077] During the RF reception stage, the detected part emits a feedback signal, and the magnetic field has a relatively small field strength. The induced voltage generated by the magnetic field enhancement component 10 is relatively small. The applied voltage cannot reach the turn-on voltages of the fifth diode 461 and the sixth diode 462, so the fifth diode 461 and the sixth diode 462 do not conduct. The first resonant capacitor 911 is electrically connected to two adjacent magnetic field enhancement components 10 respectively, and current passes through. The magnetic field enhancement device 20 is in a resonant state and plays a role in enhancing the magnetic field.

[0078] In one embodiment, the magnetic field enhancement device 20 further includes a sixth external capacitor 4451, a first external diode 4611, and a second external diode 4622. The connection relationships of the sixth external capacitor 4451, the first external diode 4611, and the second external diode 4622 with the second resonant capacitor 921 are the same as the connection relationships of the fifth diode 461, the sixth diode 462, and the fifth external capacitor 445 with the first resonant capacitor 911 respectively, and the working principles are also the same. Reference can be made to the description in the above embodiment.

[0079] During the radio frequency signal transmission stage, the second resonant capacitor 921 is disconnected from two adjacent magnetic field enhancement components 10 respectively, no current passes through, and it is in a detuned state. The magnetic field generated by the magnetic field enhancement device 20 weakens, thereby reducing the influence of the magnetic field enhancement device 20 on the magnetic field during the radio frequency signal transmission stage, reducing the artifacts in the detected image, and improving the clarity of the detected image. During the radio frequency reception stage, the second resonant capacitor 921 is electrically connected to two adjacent magnetic field enhancement components 10 respectively, and current passes through. The magnetic field enhancement device 20 is in a resonant state and plays a role in enhancing the magnetic field.

[0080] Please refer to Figure 8 , in one embodiment, the magnetic field enhancement device 20 further includes a first depletion MOS transistor 231 and a second depletion MOS transistor 232. The source electrode of the first depletion MOS transistor 231 is electrically connected to the first electrode layer 110 located in the first capacitor region 11, and the gate electrode and the drain electrode of the first depletion MOS transistor 231 are electrically connected. The gate electrode and the drain electrode of the second depletion MOS transistor 232 are electrically connected. The gate electrode and the drain electrode of the second depletion MOS transistor 232 are electrically connected to the gate electrode and the drain electrode of the first depletion MOS transistor 231. One end of the first resonant capacitor 911 is electrically connected to the source electrode of the second depletion MOS transistor 232. The other end of the first resonant capacitor 911 is electrically connected to the second electrode layer 120.

[0081] The first depletion MOS transistor 231 and the second depletion MOS transistor 232 are connected in reverse series, which can control the disconnection between the first electrode layer 110 and the second electrode layer 120 during the radio frequency transmission stage and the connection during the radio frequency reception stage. By connecting the first depletion MOS transistor 231 and the second depletion MOS transistor 232 in reverse series, it can adapt to the AC environment in the MRI device. The first depletion MOS transistor 231 and the second depletion MOS transistor 232 are connected in reverse series, which can ensure that one of the first depletion MOS transistor 231 and the second depletion MOS transistor 232 is cut off during the radio frequency transmission stage, so that the circuit where the first resonant capacitor 911 is located is in an open circuit and is not electrically connected to the second electrode layer 120 and the first electrode layer 110.

[0082] The first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 have the characteristics of conducting at low voltage and cutting off at high voltage. Moreover, the pinch-off voltages of the first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 at room temperature are about 1V, and both the turn-off time and the recovery time are in the nanosecond order. There is a difference of several tens of milliseconds to several thousand milliseconds in the time sequence between the radio frequency transmission stage and the radio frequency reception stage in the MRI device, and the first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 can be quickly turned on and off. The radio frequency powers in the radio frequency transmission stage and the radio frequency reception stage differ by three orders of magnitude. The induced voltage in the coil during the radio frequency transmission stage is between several volts and several hundred volts, and the specific value is related to the selected sequence and flip angle.

[0083] During the radio frequency transmission stage, the induced voltage is large, the first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 are in the off state, the circuit where the first resonant capacitor 911 is located is in an open circuit and is not electrically connected to the second electrode layer 120 and the first electrode layer 110. The magnetic field enhancement device 20 is in a detuned state. There is no current in the magnetic field enhancement device 20, and no induced magnetic field that will interfere with the radio frequency is generated. During the radio frequency reception stage, the first depletion-mode MOS transistor 231 and the second depletion-mode MOS transistor 232 are turned on, the circuit where the first resonant capacitor 911 is located is in a conducting state, and both ends are electrically connected to the second electrode layer 120 and the first electrode layer 110 respectively. The magnetic field enhancement device 20 can present a resonant state, greatly enhancing the signal field and enhancing the image signal-to-noise ratio.

[0084] In one embodiment, the magnetic field enhancement device 20 further includes a third depletion-mode MOS transistor 2311 and a fourth depletion-mode MOS transistor 2321. The source electrode of the third depletion-mode MOS transistor 2311 is electrically connected to the first electrode layer 110 located in the first capacitor region 11. The gate and drain electrodes of the third depletion-mode MOS transistor 2311 are electrically connected. The gate and drain electrodes of the fourth depletion-mode MOS transistor 2321 are electrically connected. The gate and drain electrodes of the fourth depletion-mode MOS transistor 2321 are electrically connected to the gate and drain electrodes of the third depletion-mode MOS transistor 2311. One end of the second resonant capacitor 921 is electrically connected to the source electrode of the fourth depletion-mode MOS transistor 2321. The other end of the second resonant capacitor 921 is electrically connected to the third electrode layer 130.

[0085] The connection relationship of the third depletion-mode MOS transistor 2311, the fourth depletion-mode MOS transistor 2321, and the second resonant capacitor 921 is the same as the connection relationship of the first depletion-mode MOS transistor 231, the second depletion-mode MOS transistor 232, and the first resonant capacitor 911, and their working principles are also the same. For details, please refer to the above embodiments.

[0086] The connection relationship of the third depletion-type MOS transistor 2311, the fourth depletion-type MOS transistor 2321, the second resonant capacitor 921, the first depletion-type MOS transistor 231, the second depletion-type MOS transistor 232, and the first resonant capacitor 911 forms a symmetric structure, which can further make the magnetic field more uniform and symmetric, facilitating imaging.

[0087] In one embodiment, the third electrode layer 130 and the second electrode layer 120 are not collinear. The third electrode layer 130 and the second electrode layer 120 are respectively disposed on the geometric diagonals of the first surface 101.

[0088] Please refer to Figure 9 , in one embodiment, the present application provides a magnetic field enhancement device 20. The magnetic field enhancement device 20 includes a plurality of magnetic field enhancement components 10. Each magnetic field enhancement component 10 includes a first dielectric layer 100 and a first electrode layer 110. The first dielectric layer 100 has a first end 103 and a second end 104 disposed opposite to each other. The first dielectric layer 100 further has a first surface 101 extending from the first end 103 to the second end 104. In the direction from the first end 103 to the second end 104, the first surface 101 includes a first capacitance region 11, a conduction region 13, and a second capacitance region 12. The conduction region 13 is located between the first capacitance region 11 and the second capacitance region 12. The first capacitance region 11 is close to the first end 103. The second capacitance region 12 is close to the second end 104.

[0089] The first electrode layer 110 is disposed on the first surface 101. The first electrode layer 110 extends from the first end 103 to the second end 104. The first electrode layer 110 covers the first surface 101. Each magnetic field enhancement component 10 extends from the first end 103 to the second end 104.

[0090] Please refer to Figure 10 , the plurality of magnetic field enhancement components 10 are spaced apart. The plurality of magnetic field enhancement components 10 enclose to form a magnetic field enhancement space 105.

[0091] The magnetic field enhancement device 20 further includes a plurality of first resonant capacitors 911 and a plurality of second resonant capacitors 921. The plurality of first resonant capacitors 911 are disposed near the first end 103. Each of the first resonant capacitors 911 is disposed between two adjacent magnetic field enhancement components 10. Two ends of each first resonant capacitor 911 are respectively electrically connected to the first electrode layers 110 located in the first capacitor region 11 of two adjacent magnetic field enhancement components 10. That is, one end of the first resonant capacitor 911 is electrically connected to the first electrode layer 110 located in the first capacitor region 11 of one magnetic field enhancement component 10, and the other end of the first resonant capacitor 911 is electrically connected to the first electrode layer 110 located in the first capacitor region 11 of an adjacent magnetic field enhancement component 10.

[0092] On one side of the first end 103, the plurality of magnetic field enhancement components 10 are connected by the plurality of first resonant capacitors 911. When the magnetic field enhancement device 20 is disposed in a magnetic field environment, an induced current will be generated. On one side of the first end 103, the induced current will sequentially pass through the portion of the first electrode layer 110 located in the first capacitor region 11, two ends of the first resonant capacitor 911, the portion of the first electrode layer 110 located in the first capacitor region 11 of an adjacent magnetic field enhancement component 10, two ends of the first resonant capacitor 911, etc. Please refer to Figure 4 , when equivalent to a circuit diagram, the plurality of first resonant capacitors 911 are connected in series one by one in sequence.

[0093] The plurality of second resonant capacitors 921 are disposed near the second end 104. Each of the second resonant capacitors 921 is disposed between two adjacent magnetic field enhancement components 10. Two ends of each second resonant capacitor 921 are respectively electrically connected to the first electrode layers 110 located in the second capacitor region 12 of two adjacent magnetic field enhancement components 10. That is, one end of the second resonant capacitor 921 is electrically connected to the first electrode layer 110 located in the second capacitor region 12 of one magnetic field enhancement component 10, and the other end of the second resonant capacitor 921 is electrically connected to the first electrode layer 110 located in the second capacitor region 12 of an adjacent magnetic field enhancement component 10.

[0094] On one side of the second end 104, the multiple magnetic field enhancement components 10 are connected through the multiple second resonant capacitors 921. When the magnetic field enhancement device 20 is disposed in a magnetic field environment, an induced current will be generated. On one side of the second end 104, the induced current will sequentially pass through the portion of the first electrode layer 110 located in the second capacitor region 12, both ends of the second resonant capacitor 921, the portion of the first electrode layer 110 of the adjacent magnetic field enhancement component 10 located in the second capacitor region 12, both ends of the second resonant capacitor 921, etc. Please refer to Figure 4 , when equivalent to a circuit diagram, the multiple second resonant capacitors 921 are connected in series one by one in sequence.

[0095] The first electrode layer 110 covers the first surface 101 and no parallel plate capacitor is formed. When the multiple magnetic field enhancement components 10 are connected and placed in a magnetic field environment, the multiple first resonant capacitors 911 are connected in series one by one in sequence. The multiple second resonant capacitors 921 are connected in series one by one in sequence.

[0096] Since capacitance is inversely proportional to frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency is relatively large, which will make the equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components need to be relatively small. However, the series connection of the multiple first resonant capacitors 911 will make the equivalent capacitance formed by the multiple first resonant capacitors 911 become smaller. The series connection of the multiple second resonant capacitors 921 will make the equivalent capacitance formed by the multiple second resonant capacitors 921 become smaller. When the capacitance values in the resonant frequency of the magnetic field enhancement device 20 are allocated to the multiple first resonant capacitors 911 and the multiple second resonant capacitors 921, the capacitance values of the multiple first resonant capacitors 911 and the multiple second resonant capacitors 921 can adopt large capacitance values, avoiding the use of capacitors with too small capacitance values. Using capacitors with large capacitance values makes the resonant frequency of the magnetic field enhancement device 20 fluctuate less, improves the stability of the resonant frequency, and is more suitable for high-field MRI.

[0097] Please refer to Figure 11 , in one embodiment, the magnetic field enhancement device 20 further includes multiple third conductive structures 539 and multiple fourth conductive structures 549. The multiple third conductive structures 539 are disposed close to the first end 103. The multiple fourth conductive structures 549 are disposed close to the second end 104.

[0098] In one embodiment, the third conductive structure 539 and the fourth conductive structure 549 have a conductive function. The materials of the third conductive structure 539 and the fourth conductive structure 549 can be made of metal materials such as gold, silver, and copper.

[0099] Please refer to Figure 12, each of the third conductive structures 539 is disposed on the surface of each first electrode layer 110 away from the first dielectric layer 100. One of the third conductive structures 539 is correspondingly disposed with one of the magnetic field enhancement components 10. Two ends of each first resonant capacitor 911 are electrically connected to two adjacent third conductive structures 539 respectively. That is, one end of a first resonant capacitor 911 is electrically connected to a third conductive structure 539, and the other end of the first resonant capacitor 911 is electrically connected to an adjacent third conductive structure 539. When equivalent to a circuit diagram, the multiple first resonant capacitors 911 are connected in series in sequence through the multiple third conductive structures 539.

[0100] , each of the fourth conductive structures 549 is disposed on the surface of each first electrode layer 110 away from the first dielectric layer 100. One of the fourth conductive structures 549 is correspondingly disposed with one of the magnetic field enhancement components 10. Two ends of each second resonant capacitor 921 are electrically connected to two adjacent fourth conductive structures 549 respectively. That is, one end of a second resonant capacitor 921 is electrically connected to a fourth conductive structure 549, and the other end of the second resonant capacitor 921 is electrically connected to an adjacent fourth conductive structure 549. When equivalent to a circuit diagram, the multiple second resonant capacitors 921 are connected in series in sequence through the multiple fourth conductive structures 549.

[0101] Please refer to Figure 13 , in one embodiment, the magnetic field enhancement device 20 further includes a first inductor 241, a third diode 213, and a fourth diode 214. One end of the first inductor 241 is electrically connected to one end of the first resonant capacitor 911. The anode of the third diode 213 is electrically connected to the other end of the first resonant capacitor 911. The cathode of the third diode 213 is electrically connected to the other end of the first inductor 241. The cathode of the fourth diode 214 is electrically connected to the other end of the first resonant capacitor 911. The anode of the fourth diode 214 is electrically connected to the other end of the first inductor 241.

[0102] In an MRI system, to enhance the magnetic field strength of the human body feedback signal in the radio frequency receiving stage. In the radio frequency transmitting stage of the MRI system, the magnetic field energy in the transmitting stage is more than 1000 times that in the receiving stage. The induced voltage in the transmitting stage is between several tens of volts and several hundreds of volts. The induced voltage in the receiving stage is less than 1V.

[0103] The third diode 213 and the fourth diode 214 are connected in reverse parallel. During the radio frequency (RF) transmission stage, the RF coil emits an RF transmission signal, and the magnetic field has a relatively large field strength. The induced voltage generated by the magnetic field enhancement component 10 is relatively large. The voltages applied across the third diode 213 and the fourth diode 214 alternate in polarity. When the applied voltage exceeds the turn-on voltages of the third diode 213 and the fourth diode 214, the third diode 213 and the fourth diode 214 conduct. The third capacitor is connected in parallel with the first inductor 241, causing the circuit formed by the first resonant capacitor 911, the third diode 213, the fourth diode 214, and the first inductor 241 to be in a high-impedance state. During the RF signal transmission stage, there is almost no current flowing between two adjacent magnetic field enhancement components 10. The first resonant capacitor 911 is disconnected from the first electrode layers 110 of two adjacent magnetic field enhancement components 10, and almost no current passes through. The magnetic field generated by the magnetic field enhancement device 20 weakens, thereby reducing the influence of the magnetic field enhancement device 20 on the magnetic field during the RF signal transmission stage, reducing artifacts in the detected image, and improving the clarity of the detected image.

[0104] During the RF reception stage, the detected part emits a feedback signal, and the magnetic field has a relatively small field strength. The induced voltage generated by the magnetic field enhancement component 10 is relatively small. The applied voltage cannot reach the turn-on voltages of the third diode 213 and the fourth diode 214, so the third diode 213 and the fourth diode 214 do not conduct. The first resonant capacitor 911 is electrically connected to the first electrode layers 110 of two adjacent magnetic field enhancement components 10, and current passes through. The magnetic field enhancement device 20 is in a resonant state and functions to enhance the magnetic field.

[0105] In one embodiment, the magnetic field enhancement device 20 further includes a seventh diode 2131, an eighth diode 2141, and a second inductor 2411. The connection relationships of the seventh diode 2131, the eighth diode 2141, and the second inductor 2411 with the second resonant capacitor 921 are the same as the connection relationships of the first inductor 241, the third diode 213, and the fourth diode 214 with the first resonant capacitor 911 respectively, and the working principles are also the same. Reference can be made to the description of the above embodiment. During the RF generation stage, the second resonant capacitor 921 is disconnected from the first electrode layers 110 of two adjacent magnetic field enhancement components 10, no current passes through, and it is in a detuned state. During the RF reception stage, the second resonant capacitor 921 is electrically connected to the first electrode layers 110 of two adjacent magnetic field enhancement components 10, and current passes through. The magnetic field enhancement device 20 is in a resonant state and functions to enhance the magnetic field.

[0106] Please refer toFigure 14 In one embodiment, the present application provides a magnetic field enhancement device 20. The magnetic field enhancement device 20 includes a plurality of magnetic field enhancement components 10. Each magnetic field enhancement component 10 includes a first dielectric layer 100, a first electrode layer 110, a second electrode layer 120, and a fourth electrode layer 140. The first dielectric layer 100 has a first end 103 and a second end 104 disposed opposite to each other. The first dielectric layer 100 has a first surface 101 and a second surface 102 disposed opposite to each other, extending from the first end 103 to the second end 104.

[0107] The first surface 101 includes a first capacitance region 11, a conduction region 13, and a second capacitance region 12. The conduction region 13 is located between the first capacitance region 11 and the second capacitance region 12. The first capacitance region 11 is close to the first end 103. The second capacitance region 12 is close to the second end 104. The first electrode layer 110 is disposed on the first surface 101, extending from the first end 103 to the second end 104, and covering the first surface 101.

[0108] The second electrode layer 120 is disposed on the second surface 102. The second electrode layer 120 is located in the second capacitance region 12. The orthographic projection of the second electrode layer 120 on the first dielectric layer 100 is located in the orthographic projection of the first electrode layer 110 on the first dielectric layer 100, forming a second structural capacitance 152.

[0109] The fourth electrode layer 140 is disposed on the second surface 102. The fourth electrode layer 140 is spaced apart from the second electrode layer 120. The fourth electrode layer 140 is located in the first capacitance region 11. The orthographic projection of the fourth electrode layer 140 on the first dielectric layer 100 is located in the orthographic projection of the first electrode layer 110 on the first dielectric layer 100, forming a first structural capacitance 151.

[0110] Each magnetic field enhancement component 10 extends from the first end 103 to the second end 104. The plurality of magnetic field enhancement components 10 are spaced apart and surround to form a magnetic field enhancement space 105.

[0111] Please refer to Figure 15 , in the first capacitance region 11, the first electrode layer 110 and the fourth electrode layer 140 of two adjacent magnetic field enhancement components 10 are connected.

[0112] When the magnetic field enhancement device 20 is disposed in a magnetic field environment, an induced current will be generated. On one side of the first end 103, the adjacent two first structural capacitors 151 are connected through the first electrode layer 110 and the fourth electrode layer 140. The induced current will pass through the first structural capacitors 151 one by one in sequence. When equivalent to a circuit diagram, the multiple first structural capacitors 151 are connected in series one by one in sequence.

[0113] Please refer to Figure 16 , in the second capacitor region 12, the first electrode layer 110 and the second electrode layer 120 of the adjacent two magnetic field enhancement components 10 are connected.

[0114] When the magnetic field enhancement device 20 is disposed in a magnetic field environment, an induced current will be generated. On one side of the second end 104, the adjacent two second structural capacitors 152 are connected through the first electrode layer 110 and the second electrode layer 120. The induced current will pass through the second structural capacitors 152 one by one in sequence. When equivalent to a circuit diagram, the multiple second structural capacitors 152 are connected in series one by one in sequence.

[0115] When the multiple magnetic field enhancement components 10 are connected and placed in a magnetic field environment, the multiple first structural capacitors 151 are connected in series one by one in sequence. The multiple second structural capacitors 152 are connected in series one by one in sequence. When the operating frequency of a high-field or ultra-high-field MRI system (3T and above) is the same as the resonance frequency of the magnetic field enhancement device 20, the magnetic field enhancement device 20 can enhance the magnetic field.

[0116] Since capacitance is inversely proportional to frequency, in a high-field or ultra-high-field MRI system (3T and above), the frequency is relatively large, which will make the equivalent capacitance of the structure formed by connecting multiple traditional magnetic field enhancement components need to be relatively small. However, the multiple first structural capacitors 151 are connected in series one by one in sequence, which will make the equivalent capacitance formed by the multiple first structural capacitors 151 become smaller. The multiple second structural capacitors 152 are connected in series one by one in sequence, which will make the equivalent capacitance formed by the multiple second structural capacitors 152 become smaller. The multiple second structural capacitors 152 and the multiple first structural capacitors 151 can form a structure with a relatively large capacitance value, making the resonance frequency fluctuation of the magnetic field enhancement device 20 smaller, improving the stability of the resonance frequency, and being more suitable for high-field MRI.

[0117] In one embodiment, the magnetic field enhancement device 20 further includes a plurality of fifth conductive structures 559 and a plurality of sixth conductive structures 569. The plurality of first structural capacitors 151 are sequentially connected in series through the plurality of fifth conductive structures 559. The plurality of second structural capacitors 152 are sequentially connected in series through the plurality of sixth conductive structures 569. The plurality of fifth conductive structures 559 and the plurality of sixth conductive structures 569 have a conductive function. The materials of the plurality of fifth conductive structures 559 and the plurality of sixth conductive structures 569 can be made of metal materials such as gold, silver, and copper.

[0118] Please refer to Figure 17 , in one embodiment, the magnetic field enhancement device 20 further includes a first external capacitor 440, a first diode 431, and a second diode 432. Two ends of the first external capacitor 440 are respectively electrically connected to parts of the second electrode layer 120 and the first electrode layer 110 located in the second capacitor region 12. The anode of the first diode 431 is electrically connected to the part of the first electrode layer 110 located in the second capacitor region 12. The cathode of the first diode 431 is electrically connected to the second electrode layer 120. The cathode of the second diode 432 is electrically connected to the part of the first electrode layer 110 located in the second capacitor region 12. The anode of the second diode 432 is electrically connected to the second electrode layer 120.

[0119] It can be understood that the conduction voltages of the first diode 431 and the second diode 432 can be between 0 volts and 1 volt. In one embodiment, the conduction voltages of the first diode 431 and the second diode 432 can be 0.8V. In the second capacitor region 12, the first diode 431 and the second diode 432 are respectively connected in series between the first electrode layer 110 and the second electrode layer 120, and the first diode 431 and the second diode 432 are reversely connected.

[0120] Due to the alternating current characteristics of the radio frequency. The induced voltages generated by the first electrode layer 110 and the second electrode layer 120 are also alternating current voltages. During the radio frequency transmission stage, since the voltage difference between the first electrode layer 110 and the second electrode layer 120 has exceeded the conduction voltages of the first diode 431 and the second diode 432. Therefore, no matter which of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, one of the first diode 431 and the second diode 432 is always in a conducting state. Therefore, the first electrode layer 110 and the second electrode layer 120 are electrically connected. The first external capacitor 440 is short-circuited. The magnetic field enhancement device 20 is in a detuned state.

[0121] In the radio frequency receiving stage, since the voltage difference between the first electrode layer 110 and the second electrode layer 120 is less than the conduction voltages of the first diode 431 and the second diode 432. Therefore, regardless of which of the first electrode layer 110 and the second electrode layer 120 has a higher voltage, the first diode 431 and the second diode 432 are both in a non-conducting state. The magnetic field enhancement device 20 is in a resonant state.

[0122] In one embodiment, in the first capacitor region 11, the first electrode layer 110 and the fourth electrode layer 140 can also be electrically connected to the first external capacitor 440, the first diode 431, and the second diode 432 respectively, and the connection relationships are the same. The magnetic field enhancement device 20 forms a symmetric structure at the first end 103 and the second end 104, which is more conducive to the uniform distribution of the magnetic field and improves the imaging quality of the MRI device.

[0123] In one embodiment, the component capacitor in the above embodiment can be a fixed capacitor or an adjustable capacitor. When the frequency of the radio frequency coil is determined, a suitable fixed capacitor can be selected for the component capacitor, so that the fixed capacitor cooperates with other structural capacitors and component capacitors to make the resonant frequency of the magnetic field enhancement device 20 equal to the frequency of the radio frequency coil, thereby enhancing the magnetic field. When the frequency of the radio frequency coil is uncertain, the component capacitor can be an adjustable capacitor. By adjusting the adjustable capacitor, the resonant frequency is adjusted so that the magnetic field enhancement device 20 is suitable for different working environments.

[0124] Please refer to Figure 18 and Figure 19 , in one embodiment, the magnetic field enhancement device 20 further includes a cylindrical support structure 50. The cylindrical support structure 50 has two relatively spaced third ends 51 and fourth ends 53. The cylindrical support structure 50 has an inner surface 521 and an outer surface 522 that are relatively spaced apart. The inner surface 521 encloses a detection space 509. The plurality of magnetic field enhancement components 10 are spaced apart on the outer surface 522. The magnetic field enhancement components 10 extend from the third end 51 to the fourth end 53.

[0125] The detection space 509 can be used to accommodate a detection part. The detection part can be an arm, a leg, an abdomen, etc. The equal spacing distance of the plurality of magnetic field enhancement components 10 can improve the uniformity of the local magnetic field. The plurality of magnetic field enhancement components 10 can be equally spaced on the outer surface 522 of the cylindrical support structure 50.

[0126] In one embodiment, a plurality of limiting structures 550 are spaced apart around the outer surface 522 of the cylindrical support structure 50. In the direction from the third end 51 to the fourth end 53, each magnetic field enhancement component 10 corresponds to the limiting structure 550 at the third end 51 and the limiting structure 550 at the fourth end 53 respectively. One magnetic field enhancement component 10 is fixed by the limiting structures 550 at both ends of the third end 51 and the fourth end 53, and thus the magnetic field enhancement component 10 is fixed to the cylindrical support structure 50.

[0127] In one embodiment, the limiting structure 550 can be a through groove. The through groove can be used to insert the magnetic field enhancement component 10. The two through grooves respectively limit both ends of the magnetic field enhancement component 10. The magnetic field enhancement component 10 can be fixed to the outer surface 522 of the cylindrical support structure 50 through the limiting structure 550.

[0128] In one embodiment, the magnetic field enhancement device 20 can include 12 magnetic field enhancement components 10, which are arranged at equal intervals around the axis on the outer surface 522 of the cylindrical support structure 50.

[0129] In one embodiment, in the direction from the first end 103 to the second end 104, the length of the first electrode layer 110 is 100 mm, and the width of the first electrode layer 110 is 15 mm. In the direction from the first end 103 to the second end 104, the widths of the first conductive structure 519, the second conductive structure 529, the third conductive structure 539, and the fourth conductive structure 549 are 10 mm. The diameter of the magnetic field enhancement device 20 is 100 mm.

[0130] Please refer to Figure 20 , in one embodiment, when the traditional structure and the magnetic field enhancement device of the present application are applied to a 7T MRI system, it can be seen that: for magnetic field enhancement devices of the same length, in order to meet the requirements of a 7T MRI system, the capacitance value required by the traditional structure is 0.6 pF, which is much smaller than the capacitance values of currently commonly used capacitors. However, the capacitance value required by the magnetic field enhancement device 20 in the present application is 6 pF, which is a commonly used capacitance value in the market. Compared with the capacitance value of 0.6 pF required by the traditional structure, when the capacitance value increases by 1 pF, the resonance frequency of the traditional structure decreases by 75.5 MHz. However, the resonance frequency of the magnetic field enhancement device 20 in the present application only decreases by 22.8 MHz. Therefore, in the high-frequency band, the structure of the magnetic field enhancement device 20 in the present application is more stable. The magnetic field enhancement device 20 has a relatively slow rate of change of the resonance frequency with capacitance, making the tuning of the structure easier to operate and more suitable for high-field MRI. Please refer to Figure 21, it can be seen that the magnetic field enhancement device 20 of the present application still has a highly uniform magnetic field distribution in the high-frequency band.

[0131] In the description of this specification, the description with reference to terms such as "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or features described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example. The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope described in this specification. The above-described embodiments only represent several implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the patent application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A magnetic field enhancement device, characterized in that, it includes: a plurality of magnetic field enhancement components (10), each of the magnetic field enhancement components (10) includes: a first dielectric layer (100) having a first end (103) and a second end (104) disposed opposite to each other, the first dielectric layer (100) further having a first surface (101) extending from the first end (103) to the second end (104), the first surface (101) including a first capacitance region (11), a conduction region (13), and a second capacitance region (12), the conduction region (13) being located between the first capacitance region (11) and the second capacitance region (12), the first capacitance region (11) being close to the first end (103), and the second capacitance region (12) being close to the second end (104); a first electrode layer (110) disposed on the first surface (101) and extending from the first end (103) to the second end (104); a second electrode layer (120) disposed on the first surface (101) and located in the first capacitance region (11), the second electrode layer (120) being spaced apart from a portion of the first electrode layer (110) located in the first capacitance region (11); a third electrode layer (130) disposed on the first surface (101) and located in the second capacitance region (12), the third electrode layer (130) being spaced apart from a portion of the first electrode layer (110) located in the second capacitance region (12); each of the magnetic field enhancement components (10) extends from the first end (103) to the second end (104), the plurality of magnetic field enhancement components (10) are spaced apart and enclose to form a magnetic field enhancement space (105); a plurality of first resonant capacitors (911) disposed close to the first end (103), one of the first resonant capacitors (911) being correspondingly disposed with one of the magnetic field enhancement components (10), one end of each of the first resonant capacitors (911) being electrically connected to the second electrode layer (120), the other end of each of the first resonant capacitors (911) being electrically connected to a portion of the first electrode layer (110) located in the first capacitance region (11), and the second electrode layers (120) of adjacent two of the magnetic field enhancement components (10) being connected to a portion of the first electrode layer (110) located in the first capacitance region (11); a plurality of second resonant capacitors (921) disposed close to the second end (104), one of the second resonant capacitors (921) being correspondingly disposed with one of the magnetic field enhancement components (10), one end of each of the second resonant capacitors (921) being electrically connected to the third electrode layer (130), the other end of each of the second resonant capacitors (921) being electrically connected to a portion of the first electrode layer (110) located in the second capacitance region (12), and the third electrode layers (130) of adjacent two of the magnetic field enhancement components (10) being connected to a portion of the first electrode layer (110) located in the second capacitance region (12).

2. The magnetic field enhancement device according to claim 1, wherein, in the first capacitor region (11), the first resonant capacitor (911) is disposed on the first surface (101); in the second capacitor region (12), the second resonant capacitor (921) is disposed on the first surface (101).

3. The magnetic field enhancement device according to claim 1, wherein, further comprising: a plurality of first conductive structures (519), disposed near the first end (103), and each of the first conductive structures (519) is disposed between two adjacent magnetic field enhancement components (10); both ends of each of the first conductive structures (519) are respectively connected to the portions of the second electrode layer (120) and the first electrode layer (110) of two adjacent magnetic field enhancement components (10) located in the first capacitor region (11); a plurality of second conductive structures (529), disposed near the second end (104), and each of the second conductive structures (529) is disposed between two adjacent magnetic field enhancement components (10); both ends of each of the second conductive structures (529) are respectively connected to the portions of the third electrode layer (130) and the first electrode layer (110) of two adjacent magnetic field enhancement components (10) located in the second capacitor region (12).

4. The magnetic field enhancement device according to claim 1, wherein, further comprising: a fifth diode (461), an anode of the fifth diode (461) is electrically connected to the second electrode layer (120); a sixth diode (462), a cathode of the sixth diode (462) is electrically connected to the second electrode layer (120); and a fifth external capacitor (445), one end of the fifth external capacitor (445) is electrically connected to the first electrode layer (110) located in the first capacitor region (11), and the other end of the fifth external capacitor (445) is electrically connected to the cathode of the fifth diode (461) and the anode of the sixth diode (462) respectively.

5. The magnetic field enhancement device according to claim 1, wherein, further comprising: a first depletion MOS transistor (231), a source of the first depletion MOS transistor (231) is electrically connected to the first electrode layer (110) located in the first capacitor region (11), and a gate and a drain of the first depletion MOS transistor (231) are electrically connected; a second depletion MOS transistor (232), a gate and a drain of the second depletion MOS transistor (232) are electrically connected and are electrically connected to the gate and the drain of the first depletion MOS transistor (231); one end of the first resonant capacitor (911) is electrically connected to the source of the second depletion MOS transistor (232), and the other end of the first resonant capacitor (911) is electrically connected to the second electrode layer (120).

6. A magnetic field enhancement device, wherein, comprising: a plurality of magnetic field enhancement components (10), each of the magnetic field enhancement components (10) comprising: The first dielectric layer (100) has a first end (103) and a second end (104) disposed opposite to each other. The first dielectric layer (100) further has a first surface (101) extending from the first end (103) to the second end (104). The first surface (101) includes a first capacitance region (11), a conduction region (13), and a second capacitance region (12). The conduction region (13) is located between the first capacitance region (11) and the second capacitance region (12). The first capacitance region (11) is close to the first end (103), and the second capacitance region (12) is close to the second end (104). The first electrode layer (110) is disposed on the first surface (101), extends from the first end (103) to the second end (104), and covers the first surface (101). Each of the magnetic field enhancement components (10) extends from the first end (103) to the second end (104). The plurality of magnetic field enhancement components (10) are spaced apart and enclose a magnetic field enhancement space (105). A plurality of first resonant capacitors (911) are disposed close to the first end (103). Each of the first resonant capacitors (911) is disposed between two adjacent magnetic field enhancement components (10). Two ends of the first resonant capacitor (911) are respectively electrically connected to the first electrode layer (110) located in the first capacitance region (11) of two adjacent magnetic field enhancement components (10). A plurality of second resonant capacitors (921) are disposed close to the second end (104). Each of the second resonant capacitors (921) is disposed between two adjacent magnetic field enhancement components (10). Two ends of the second resonant capacitor (921) are respectively electrically connected to the first electrode layer (110) located in the second capacitance region (12) of two adjacent magnetic field enhancement components (10).

7. The magnetic field enhancement device according to claim 6, wherein, it further includes: A plurality of third conductive structures (539) are disposed close to the first end (103), and each of the third conductive structures (539) is disposed on the surface of each first electrode layer (110) away from the first dielectric layer (100); Two ends of each of the first resonant capacitors (911) are respectively electrically connected to two adjacent third conductive structures (539); A plurality of fourth conductive structures (549) are disposed close to the second end (104), and each of the fourth conductive structures (549) is disposed on the surface of each first electrode layer (110) away from the first dielectric layer (100); Two ends of each of the second resonant capacitors (921) are respectively electrically connected to two adjacent fourth conductive structures (549).

8. The magnetic field enhancement device according to claim 6, wherein, it further includes: A first inductor (241), one end of the first inductor (241) is electrically connected to one end of the first resonant capacitor (911); A third diode (213), an anode of the third diode (213) is electrically connected to the other end of the first resonant capacitor (911), and a cathode of the third diode (213) is electrically connected to the other end of the first inductor (241); A fourth diode (214), a cathode of the fourth diode (214) is electrically connected to the other end of the first resonant capacitor (911), and an anode of the fourth diode (214) is electrically connected to the other end of the first inductor (241).

9. A magnetic field enhancement device, characterized in that, comprising: a plurality of magnetic field enhancement components (10), each of the magnetic field enhancement components (10) comprising: a first dielectric layer (100) having a first end (103) and a second end (104) disposed opposite to each other, the first dielectric layer (100) having a first surface (101) and a second surface (102) disposed opposite to each other, extending from the first end (103) to the second end (104), the first surface (101) including a first capacitance region (11), a conduction region (13), and a second capacitance region (12), the conduction region (13) being located between the first capacitance region (11) and the second capacitance region (12), the first capacitance region (11) being close to the first end (103), and the second capacitance region (12) being close to the second end (104); a first electrode layer (110) disposed on the first surface (101), extending from the first end (103) to the second end (104), and covering the first surface (101); a second electrode layer (120) disposed on the second surface (102) and located in the second capacitance region (12), a positive projection of the second electrode layer (120) on the first dielectric layer (100) being located in a positive projection of the first electrode layer (110) on the first dielectric layer (100) to form a second structural capacitance (152); a fourth electrode layer (140) disposed on the second surface (102), spaced apart from the second electrode layer (120), and located in the first capacitance region (11), a positive projection of the fourth electrode layer (140) on the first dielectric layer (100) being located in a positive projection of the first electrode layer (110) on the first dielectric layer (100) to form a first structural capacitance (151); each of the magnetic field enhancement components (10) extends from the first end (103) to the second end (104), the plurality of magnetic field enhancement components (10) are spaced apart and enclose to form a magnetic field enhancement space (105); in the first capacitance region (11), the first electrode layer (110) and the fourth electrode layer (140) of two adjacent magnetic field enhancement components (10) are connected; in the second capacitance region (12), the first electrode layer (110) and the second electrode layer (120) of two adjacent magnetic field enhancement components (10) are connected.

10. The magnetic field enhancement device according to claim 9, characterized in that, further comprising: A first external capacitor (440), two ends of the first external capacitor (440) are respectively electrically connected to portions of the second electrode layer (120) and the first electrode layer (110) located in the second capacitor region (12); A first diode (431), an anode of the first diode (431) is electrically connected to a portion of the first electrode layer (110) located in the second capacitor region (12), and a cathode of the first diode (431) is electrically connected to the second electrode layer (120); A second diode (432), a cathode of the second diode (432) is electrically connected to a portion of the first electrode layer (110) located in the second capacitor region (12), and an anode of the second diode (432) is electrically connected to the second electrode layer (120).

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