Resonance sound absorption structure for magnetic resonance system and magnetic resonance system

Abstract

The utility model provides a resonance sound absorption structure for a magnetic resonance system and the magnetic resonance system, and the structure comprises a first panel which is close to a gradient coil, and is provided with a plurality of micro-perforated structures; the second panel is located on the face, away from the gradient coil, of the first panel, and a sound absorption cavity is formed between the second panel and the first panel so as to cooperate with the micro-perforated structure of the first panel, and noise with the specific noise frequency is absorbed through micro-pore resonance. According to the utility model, the micropore plate is arranged on one side, close to the gradient coil, of the barrel body, the porous sound absorption layer is correspondingly arranged, and the sound absorption cavity is formed in the barrel body, so that a composite micropore resonance sound absorption structure is formed, high-frequency and low-frequency noise from the gradient coil can be effectively reduced, the noise which can be sensed by a patient is reduced, and the comfort of the patient is improved; and meanwhile, a parallel resonance sound absorption structure is adopted, and an air resonance cavity exists in the barrel, so that the weight of the barrel and the shell is reduced, and maintenance and replacement of the barrel and the shell are facilitated.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the magnetic resonance imaging equipment technical field, concretely relates to a kind of resonance sound absorption structure and magnetic resonance system for magnetic resonance system. BACKGROUND

[0002] There will be system noise when MRI system runs. The main reason for noise generation is that the electromagnetic wire inside the gradient coil passes different currents, under the action of magnet magnetic field, the electromagnetic wire inside the gradient coil will generate Lorentz magnetic force, causing the gradient coil to vibrate and generate noise, which will be transmitted through air or mechanical structure, forming the system noise of MRI. There are four transmission paths for the transmission of MRI system noise, and the most important transmission path is that noise passes through the gap (air) between the gradient coil and the cylinder from the inner surface of the gradient coil, and is directly transmitted to the cylinder through the cylinder wall thickness. The noise transmitted through this path directly affects the scanning experience of patients.

[0003] Since the generated noise is difficult to eliminate, in order to create a comfortable and quiet scanning environment for patients, the following noise reduction measures are taken on the most important propagation link of the entire MRI system noise: inserting porous sound absorption material into the end surface gap. However, due to the limitation of the gap between the gradient coil and the cylinder, the thickness of the sound absorption material cannot be thickened, and it is also not economical to increase the thickness of the sound absorption material to improve the sound absorption effect. In addition, after the porous sound absorption material is increased to a certain thickness, the sound absorption coefficient is independent of the thickness, which means that the sound absorption effect does not increase significantly. In addition to the above, a layer of sound absorption material is added to the side of the magnet close to the magnet inside the shell, and adding sound absorption material to the back of the shell will greatly increase the cost of the shell. In addition, the installation space for sound absorption material needs to be reserved at the beginning of design. In the case where the sound absorption frequency and the demand for sound absorption material are not obvious, the reserved space of the shell will be relatively conservative, which will increase the overall length of the system. UTILITY MODEL CONTENTS

[0004] In view of the above shortcomings of the prior art, the purpose of the utility model is to provide a resonance sound absorption structure and magnetic resonance system for magnetic resonance system to improve the sound absorption effect while avoiding increasing the cost and the overall length of the system.

[0005] To achieve the above object and other related objects, the utility model provides a resonance sound absorption structure for magnetic resonance system, comprising:

[0006] The first panel is close to the gradient coil, and a plurality of micro-perforated structures are distributed on the first panel.

[0007] The second panel is located on a side of the first panel away from the gradient coil, and a sound-absorbing cavity is formed between the first panel and the second panel. The second panel cooperates with the micro-perforated structure of the first panel to absorb noise with a specific noise frequency by utilizing microporous resonance.

[0008] In one embodiment of the present invention, the thickness of the sound absorbing cavity, the thickness of the first panel, and the perforation ratio of the total area of ​​the micro-perforated structure on the first panel to the area of ​​the first panel are determined according to the specific noise frequency.

[0009] In one embodiment of the present invention, the diameter of the micro-perforated structure is less than or equal to 1 mm.

[0010] In one embodiment of the present invention, the total area of ​​the micro-perforated structures on the first panel occupies 0.5% to 5% of the area of ​​the first panel.

[0011] In one embodiment of the present invention, the thickness of the sound absorbing cavity is greater than or equal to 10 mm.

[0012] In one embodiment of the present invention, a porous sound absorbing layer is further included. The porous sound absorbing layer is arranged in the sound absorbing cavity and adhered to a side of the first panel facing the second panel.

[0013] In one embodiment of the present invention, the first panel is divided into different areas.

[0014] The pore size of the micro-perforated structure in each area is the same,

[0015] Or the pore sizes of the micro-perforated structure in at least some areas are different.

[0016] In one embodiment of the present invention, a plurality of vertical ribs are provided on a side of the second panel facing the first panel. The plurality of vertical ribs can be arranged in different directions along the second panel and divide the sound absorbing cavity into a plurality of sub-cavities.

[0017] In one embodiment of the present invention, the volumes of the sub-cavities are the same, or the volumes of at least some of the sub-cavities are different.

[0018] In an embodiment of the present invention, one area of ​​the first panel corresponds to at least one sub-cavity, or one sub-cavity corresponds to at least one area of ​​the first panel.

[0019] The present invention further provides a magnetic resonance system, comprising the resonant sound absorption structure for a magnetic resonance system as described in any one of the above embodiments.

[0020] The utility model provides a resonance sound absorption structure and magnetic resonance system for magnetic resonance system, it is through setting up as the microporous plate with the side of cylinder close to gradient coil, and setting up the porous sound absorption layer correspondingly, forms the sound absorption cavity in the cylinder, forms the compound microporous resonance sound absorption structure, can effectively reduce the high frequency and low frequency noise from gradient coil, reduces the noise that patient can perceive, increases the comfort of patient, adopts the resonance sound absorption structure of parallel connection simultaneously, there will be air resonance cavity in the cylinder, like this reduces the weight of cylinder and shell, is favorable to the maintenance and replacement of cylinder and shell.

[0021] The utility model provides a resonance sound absorption structure and magnetic resonance system for magnetic resonance system, it is through changing the aperture size of microporous plate different area and / or change the volume of different sound absorption cavity to constitute the resonance sound absorption structure of different size, and the resonance sound absorption structure of different size can absorb a section frequency band respectively, can make total sound absorption frequency band wide, absorbs more noise from gradient coil, creates a more quiet nuclear magnetic resonance system. DRAWINGS

[0022] In order to more clearly illustrate the technical scheme of the embodiment of the utility model, the following will be to the embodiment description needed to use the drawing briefly introduce, obviously, the drawing in the following description only some embodiments of the utility model, for the ordinary skilled person in the art, under the premise of not paying creative labor, can also obtain other drawings according to these drawings.

[0023] Figure 1 It is the cross section structure schematic drawing of resonance sound absorption structure in an embodiment of the utility model.

[0024] Figure 2 It is the local structure schematic drawing of resonance sound absorption structure in an embodiment of the utility model.

[0025] Figure 3 It is the structure schematic drawing of one sound absorption cavity of resonance sound absorption structure in an embodiment of the utility model.

[0026] Figure 4 It is the structure schematic drawing of resonance sound absorption structure in an embodiment of the utility model.

[0027] Figure 5 It is the curve graph of single layer resonance sound absorption effect and sound absorption effect after adding sound absorption material in sound absorption cavity.

[0028] Figure 6 It is the schematic diagram of the noise reduction magnetic resonance system in an embodiment of the utility model.

[0029] Label explanation:

[0030] 111. First panel; 112. Second panel; 12. Porous sound-absorbing layer; 100. Gradient coil; 13. Sound-absorbing cavity; 11. Cylinder; 113. Micro-perforated structure; 114. Vertical ribs; 131. Sub-cavity. DETAILED DESCRIPTION

[0031] The following describes the embodiments of the present invention through specific examples. Those skilled in the art will readily understand the other advantages and benefits of the present invention from the disclosure herein. The present invention may also be implemented or applied through various other specific embodiments, and the details in this specification may be modified or altered based on different perspectives and applications without departing from the spirit of the present invention.

[0032] It should be noted that the illustrations provided in this embodiment are only used to schematically illustrate the basic concept of the present invention. Therefore, the illustrations only show components related to the present invention and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0033] See also Figures 1 to 6 As shown, the present invention provides a resonant sound absorption structure and magnetic resonance system for a magnetic resonance system to improve the sound absorption effect, so that it can effectively reduce high-frequency and low-frequency noise from the gradient coil, reduce the noise that can be perceived by the patient, and increase the patient's comfort. Specifically, the resonant sound absorption structure includes a first panel 111, a second panel 112, and a porous sound absorption layer 12. The first panel 111 is close to the gradient coil 100, and the second panel 112 is located on the side of the first panel 111 away from the gradient coil 100. A plurality of micro-perforated structures 113 are distributed on the first panel 111. A sound absorption cavity 13 is formed between the first panel 111 and the second panel 112. The micro-perforated structures 113 cooperate with the micro-perforated structures 113 of the first panel 111 to absorb noise with a specific noise frequency through microporous resonance. The porous sound absorption layer 12 is arranged in the sound absorption cavity 13 and is attached to the side of the first panel 111 facing the second panel 112. There is a gap between the porous sound absorption layer 12 and the second panel 111.

[0034] See also Figures 1 to 4As shown, it can be understood that the second panel 112 is equivalent to the cylinder 11 in the magnetic resonance system. In this embodiment, the first panel 111 and the second panel 112 can be two independent panel structures. A cavity is designed on the cylinder 11, and a layer of micro-perforated thin plate with a micro-perforated structure, i.e., the first panel 111, is covered on the cavity to form a parallel resonant sound-absorbing cavity. Then, a layer of porous sound-absorbing material, i.e., the porous sound-absorbing layer 12, is pasted on the back of the micro-perforated plate. A cavity is reserved on the back of the porous sound-absorbing material, i.e., between the porous sound-absorbing layer and the cylinder 11, thereby forming a composite microporous resonant sound-absorbing structure.

[0035] See also Figures 1 to 5 As shown, in this embodiment, when a sound wave is incident on the micro-perforated structure 113 on the first panel 111, it is equivalent to the sound wave entering from the neck of the hole. The air in the neck moves back and forth along the neck like a piston, compressing the air in the cavity. When the frequency of the incident sound wave is close to the natural frequency of the resonator, the air column in the neck produces strong vibrations, overcoming the resistance and consuming the sound energy. It can be understood that in order to further widen the sound absorption band, a porous sound absorbing layer 12 composed of a porous sound absorbing material is added to the cavity behind the first panel 111 with the micro-perforated structure 113 to form a composite micro-perforated plate resonant sound absorption structure. The composite sound absorption structure designed using porous materials and micro-perforated plates can widen the sound absorption band. The air cavity between the two layers also improves the sound absorption performance. The single-layer resonant sound absorption effect (curve 1) and the sound absorption effect after adding sound absorbing material to the sound absorption cavity (curve 2) clearly show that the sound absorption coefficient of curve 2 is significantly higher than that of curve 1.

[0036] See also Figures 1 to 3 As shown, in this embodiment, the diameter of the micro-perforated structure 113 is less than or equal to 1 mm, the total area of ​​the micro-perforated structure 113 on the first panel 111 occupies 0.5% to 5% of the area of ​​the first panel 111, the thickness of the sound-absorbing cavity 13 is greater than or equal to 10 mm, the pore diameter is less than 1 mm, and the perforation ratio is between 0.5% and 5%. This micro-perforated plate sound-absorbing structure has a wider frequency range than all other resonant sound absorbers. The peak noise of the magnetic resonance system is distributed at approximately 640 Hz and 1200 Hz, which are the so-called mid- and low-frequency frequencies. The resonant sound-absorbing structure can resonate with the 1200 Hz frequency of the magnetic resonance system, absorbing mid-frequency noise. The porous sound-absorbing material placed in the cavity can absorb higher-frequency noise. The cavity behind the sound-absorbing material can improve the absorption of low-frequency noise, thereby effectively enhancing the noise reduction effect of the sound-absorbing structure.

[0037] See also Figures 1 to 3As shown, the overall design thickness of the current cylinder 11 is 20mm. To ensure the strength and mechanical properties of the cylinder 11, in this embodiment, the minimum base wall thickness of the cylinder 11 is maintained at approximately 10mm, that is, the thickness of the second panel 112 is maintained at approximately 10mm. Therefore, in the cylinder under the composite microporous resonant sound absorption structure, the thickness of the first panel 111 can be selected, and the thickness of the sound absorption cavity can be maintained at 10mm, that is, the distance between the first panel 111 and the second panel 112 is set at 10mm. The resonant frequency (Hz) of the resonant sound absorption structure is calculated as follows:

[0038]

[0039] Where f0 is the lowest resonance frequency of the Helmholtz resonance absorber, c is the speed of sound, L is the thickness of the cavity behind the perforated plate, t is the thickness of the perforated plate, and P is the perforation ratio.

[0040] Based on the above, we can easily derive the perforation ratio of the first panel 111 at a resonant frequency of 1200 Hz. This means that a perforation ratio of 0.5% for the first panel 111 can absorb noise at a frequency of 1200 Hz. By selecting a suitable porous sound-absorbing material and accommodating the cavity formed by the sound-absorbing material, the sound absorption band can be expanded, absorbing mid- and low-frequency noise.

[0041] It can be understood that the thickness of the sound-absorbing cavity 13, the thickness of the first panel 111, and the perforation ratio of the total area of ​​the micro-perforated structure 113 on the first panel 111 to the area of ​​the first panel 111 are determined according to the specific noise frequency and can be set accordingly according to different noise frequencies.

[0042] See also Figures 1 to 3 As shown, in this embodiment, the first panel 111 can be divided into multiple different areas, each of which is distributed with a micro-perforated structure 113. In this embodiment, the pore size of the micro-perforated structure 113 in each area is the same. Of course, it can also be set so that the pore size of the micro-perforated structure 113 in at least some areas is different. That is, the pore size of the micro-perforated structure 113 in each area can be the same, or the pore size of the micro-perforated structure 113 in some areas can be the same, and the pore size of the micro-perforated structure 113 in some areas can be different, or the pore size of the micro-perforated structure 113 in each area can be different, so as to form different resonant sound absorption structures with structures such as the sound absorption cavity 13.

[0043] See also Figures 1 to 3As shown, in this embodiment, a plurality of vertical ribs 114 are provided on the side of the second panel 112 facing the first panel 111. The plurality of vertical ribs 114 can be arranged in different directions along the second panel 112 and divide the sound-absorbing cavity 13 into a plurality of sub-cavities 131. It is understood that the vertical ribs 114 can also improve its structural strength. In this embodiment, the volume of each sub-cavity 131 is the same. Of course, it is also possible to set the volume of at least some of the sub-cavities 131 to be different, that is, the volume of each sub-cavity 131 can be set to be the same, the volume of some sub-cavities 131 can be set to be the same, the volume of some sub-cavities 131 can be set to be different, or the volume of each sub-cavity 131 can be set to be different.

[0044] See also Figures 1 to 3 As shown, in this embodiment, one region of the first panel 111 corresponds to at least one sub-cavity 131, wherein the apertures of the micro-perforated structures 113 in each region can be the same or different. When the same region corresponds to multiple sub-cavities 131, the volumes of each sub-cavity 131 can be the same or different. Of course, it is also possible to configure one sub-cavity 131 to correspond to at least one region of the first panel 111. The volumes of each sub-cavity 131 can be the same or different. When the same sub-cavity 131 corresponds to multiple regions, the apertures of the micro-perforated structures 113 in each region can be the same or different, thereby forming multiple different resonant sound absorption structures, thereby broadening the overall sound absorption frequency band, absorbing more noise transmitted from the gradient coil, and creating a quieter nuclear magnetic resonance system.

[0045] See also Figures 1 to 6 As shown, in this embodiment, the present invention further provides a magnetic resonance system, including the resonant sound absorption structure for a magnetic resonance system as described in any of the above embodiments. The magnetic resonance system includes a magnet 101, a gradient coil 100, a shell 102 and a cylinder 11. The shell 102 and the cylinder 11 enclose the magnet 101 and the gradient coil 100. The cylinder 11 forms a resonant sound absorption structure. The resonant sound absorption structure is the same as or similar to the structure described in the above embodiments. To avoid repetition, it is not repeated here.

[0046] The utility model proposes a resonant sound absorption structure for a magnetic resonance system and a magnetic resonance system. The structure provides a microporous plate on one side of a cylinder close to a gradient coil, and simultaneously provides a porous sound absorption layer accordingly, so that a sound absorption cavity is formed in the cylinder to form a composite microporous resonant sound absorption structure. The structure can effectively reduce high-frequency and low-frequency noise from the gradient coil, reduce the noise perceptible to the patient, and increase the patient's comfort. At the same time, a parallel resonant sound absorption structure is adopted, and an air resonant cavity is present inside the cylinder, thereby reducing the weight of the cylinder and the outer shell, and facilitating the maintenance and replacement of the cylinder and the outer shell.

[0047] The utility model provides a resonant sound-absorbing structure for a magnetic resonance system and a magnetic resonance system. Resonant sound-absorbing structures of different sizes are formed by varying the aperture sizes of different areas of a microporous plate and / or varying the volumes of different sound-absorbing cavities. Resonant sound-absorbing structures of different sizes can each absorb a frequency band, thereby widening the overall sound-absorbing frequency band, absorbing more noise transmitted from the gradient coil, and creating a quieter nuclear magnetic resonance system.

[0048] It should be understood that references throughout this specification to "one embodiment," "an embodiment," or "a specific embodiment" mean that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention, and not necessarily in all embodiments. Thus, various appearances of the phrases "in one embodiment," "in an embodiment," or "in a specific embodiment" in different places throughout this specification are not necessarily referring to the same embodiment. Furthermore, the particular features, structures, or characteristics of any specific embodiment of the present invention may be combined with one or more other embodiments in any suitable manner. It should be understood that other variations and modifications of the embodiments of the present invention described and illustrated herein are possible in light of the teachings herein and are considered part of the spirit and scope of the present invention.

[0049] It should also be understood that one or more of the elements shown in the figures may also be implemented in a more separate or more integrated manner, or even removed because they are inoperable in certain circumstances or provided because they may be useful depending on the application.

[0050] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope involved in the present application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but should also cover other technical solutions formed by any combination of the above-mentioned technical features or their equivalent features without departing from the concept of the utility model, such as the technical solutions formed by the mutual replacement of the above-mentioned features with the technical features with similar functions disclosed in this application (but not limited to).

[0051] Except for the technical features described in the specification, the remaining technical features are known technologies to those skilled in the art. In order to highlight the innovative features of the present invention, the remaining technical features will not be described here in detail.

Claims

1. A resonant sound absorbing structure for a magnetic resonance system, characterized in that: include: a first panel, the first panel being close to the gradient coil, and having a plurality of micro-perforated structures distributed on the first panel; The second panel is located on a side of the first panel away from the gradient coil, and a sound-absorbing cavity is formed between the first panel and the second panel. The second panel cooperates with the micro-perforated structure of the first panel to absorb noise with a specific noise frequency by utilizing microporous resonance.

2. The resonant sound absorbing structure for a magnetic resonance system according to claim 1, characterized in that: The thickness of the sound absorbing cavity, the thickness of the first panel, and the perforation ratio of the total area of ​​the micro-perforated structure on the first panel to the area of ​​the first panel are determined according to the specific noise frequency.

3. The resonant sound absorbing structure for a magnetic resonance system according to claim 1, characterized in that: The diameter of the micro-perforated structure is less than or equal to 1 mm.

4. The resonant sound absorbing structure for a magnetic resonance system according to claim 1, characterized in that: The total area of ​​the micro-perforated structures on the first panel occupies 0.5% to 5% of the area of ​​the first panel.

5. The resonant sound absorbing structure for a magnetic resonance system according to claim 1, characterized in that: The thickness of the sound absorbing cavity is greater than or equal to 10 mm.

6. The resonant sound absorbing structure for a magnetic resonance system according to claim 1, characterized in that: It also includes a porous sound absorbing layer, which is arranged in the sound absorbing cavity and adhered to the side of the first panel facing the second panel.

7. The resonant sound absorbing structure for a magnetic resonance system according to claim 1, characterized in that: The first panel is divided into different areas, The pore size of the micro-perforated structure in each area is the same, Or the pore sizes of the micro-perforated structure in at least some areas are different.

8. The resonant sound absorbing structure for a magnetic resonance system according to claim 1, characterized in that: A plurality of vertical ribs are provided on a side of the second panel facing the first panel. The plurality of vertical ribs can be arranged in different directions along the second panel and divide the sound absorbing cavity into a plurality of sub-cavities.

9. The resonant sound absorbing structure for a magnetic resonance system according to claim 8, characterized in that: The volumes of the sub-cavities are the same, or at least some of the sub-cavities have different volumes.

10. The resonant sound absorbing structure for a magnetic resonance system according to claim 8, characterized in that: One area of ​​the first panel corresponds to at least one sub-cavity, or one sub-cavity corresponds to at least one area of ​​the first panel.

11. A magnetic resonance system, characterized in that: The resonant sound absorbing structure for a magnetic resonance system comprises the resonant sound absorbing structure for a magnetic resonance system according to any one of claims 1 to 10.

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