阅读说明：本技术 接收单元及磁共振设备 (Receiving unit and magnetic resonance apparatus ) 是由 徐勤 何蛟龙 马锦波 王益宁 昝国锋 于 2020-11-04 设计创作，主要内容包括：本发明公开了一种接收单元及磁共振设备。该接收单元包括能够感应并产生检测电信号的感应线圈、能够传输检测电信号的第一传输线缆以及插接组件,插接组件通过第一传输线缆与感应线圈连接,且插接组件包括信号放大器以及输出部,信号放大器的输入端与第一传输线缆电连接,信号放大器的输出端与输出部电连接。该磁共振设备采用了上述接收单元能提高信号传输质量,提高磁共振设备的成像质量。(The invention discloses a receiving unit and a magnetic resonance device. The receiving unit comprises an induction coil capable of inducing and generating a detection electric signal, a first transmission line cable capable of transmitting the detection electric signal and a plug-in assembly, wherein the plug-in assembly is connected with the induction coil through the first transmission line cable, the plug-in assembly comprises a signal amplifier and an output part, the input end of the signal amplifier is electrically connected with the first transmission line cable, and the output end of the signal amplifier is electrically connected with the output part. The magnetic resonance equipment adopts the receiving unit, so that the signal transmission quality can be improved, and the imaging quality of the magnetic resonance equipment can be improved.)

1. A receiving unit, comprising:

the induction coil can induce and generate a detection electric signal;

a first transmission cable capable of transmitting the detection electric signal; and

the plug-in assembly, the plug-in assembly pass through first transmission cable with induction coil connects, just the plug-in assembly includes signal amplifier and output part, signal amplifier's input with first transmission cable electricity is connected, signal amplifier's output with the output part electricity is connected.

2. The receiving unit of claim 1, wherein the plug assembly comprises a plug, the signal amplifier is disposed in the plug, and the plug portion of the plug is the output portion.

3. The receiving unit of claim 2, wherein an optical-to-electrical converter is disposed in the plug, an input end of the optical-to-electrical converter is electrically connected to an output end of the signal amplifier, and an output end of the optical-to-electrical converter is electrically connected to the output portion.

4. The receiving unit according to claim 2, wherein the plug assembly comprises a socket detachably connected to the plug, the socket being provided with an opto-electric converter, an input end of the opto-electric converter being detachably electrically connected to the plug portion.

5. The receiving unit of claim 1, wherein the plug assembly comprises a plug and a socket detachably connected to the plug, the signal amplifier is disposed in the socket, and the plug portion of the plug is the output portion and detachably and electrically connected to the output end of the signal amplifier.

6. The receiving unit of claim 5, wherein an optical-to-electrical converter is disposed in the socket, and an input terminal of the optical-to-electrical converter is electrically connected to an output terminal of the signal amplifier.

7. A magnetic resonance apparatus, comprising the receiving unit as claimed in any one of claims 1 to 6, wherein the plug assembly comprises a plug and a socket detachably connected to the plug, the signal amplifier is disposed on the plug or the socket, and the magnetic resonance apparatus further comprises:

the rack unit is provided with a detection cavity and comprises a support frame and a bearing plate capable of moving relative to the support frame, the support frame is arranged outside the detection cavity, and the bearing plate is fixedly provided with the socket; and

and the upper computer is electrically connected with the socket through a second transmission cable.

8. The apparatus according to claim 7, wherein the plug or the socket is provided with an optical-to-electrical converter, an input end of the optical-to-electrical converter is electrically connected with an output end of the signal amplifier, and an output end of the optical-to-electrical converter is electrically connected with the upper computer through the second transmission cable; the second transmission cable is an optical fiber.

9. The mrd of claim 7, wherein said induction coil is removably connected to said support plate.

10. The mr apparatus of any one of claims 7 to 9 further comprising a drag chain disposed between the support frame and the support plate, the drag chain being connected to the second transmission cable such that an end of the second transmission cable is movable with the drag chain.

Technical Field

The invention relates to the technical field of medical instruments, in particular to a receiving unit and magnetic resonance equipment.

Background

The magnetic resonance equipment utilizes the nuclear magnetic resonance principle, detects the emitted electromagnetic waves through an external gradient magnetic field according to different attenuations of the released energy in different structural environments in the material, so that the position and the type of the atomic nucleus forming the object can be known, and accordingly, a structural image in the object can be drawn. When the magnetic resonance equipment is used, the acquired detection electric signals are transmitted to an upper computer through an induction coil of the receiving unit, and the corresponding images are obtained after the detection electric signals are processed by the upper computer.

At present, after an induction coil induces and generates a detection electric signal, the detection electric signal is transmitted to a plug through a transmission cable, is connected with a socket through the plug, is transmitted to a receiver arranged on a rack through another transmission cable, and is amplified by a signal amplifier on the receiver and then is transmitted to an upper computer. In the process, the initial detection electric signal is transmitted in a long transmission cable, so that loss is caused, noise is introduced, signal attenuation is caused, and the improvement of the imaging quality of the magnetic resonance equipment is not facilitated.

Disclosure of Invention

In view of the above, it is desirable to provide a receiving unit and a magnetic resonance apparatus.

The technical scheme is as follows:

in one aspect, the present invention provides a receiving unit, including an induction coil capable of inducing and generating a detection electrical signal, a first transmission cable capable of transmitting the detection electrical signal, and a plug-in module, where the plug-in module is connected to the induction coil through the first transmission cable, and includes a signal amplifier and an output portion, an input end of the signal amplifier is electrically connected to the first transmission cable, and an output end of the signal amplifier is electrically connected to the output portion.

The receiving unit integrates the signal amplifier into the plug-in assembly, so that the detection electric signal generated by the induction coil can be transmitted into the signal amplifier for signal amplification only through the first transmission cable, and then the amplified detection electric signal is output by the output part. Therefore, the initial detection electric signal generated by the induction coil only needs to be transmitted through the first short transmission cable, so that the loss is low, and the influence of the transmission cable on the reduction of the signal-to-noise ratio of the initial detection signal can be reduced; and then, the signal amplifier is used for amplifying and then transmitting the electric signal at a longer distance, so that the imaging quality of the magnetic resonance equipment is improved.

The technical solution is further explained below:

in one embodiment, the plug assembly comprises a plug, a signal amplifier is arranged in the plug, and the plug part of the plug is an output part.

In one embodiment, a photoelectric converter is arranged in the plug, an input end of the photoelectric converter is electrically connected with an output end of the signal amplifier, and an output end of the photoelectric converter is electrically connected with the output part.

In one embodiment, the plug assembly includes a receptacle removably connectable to the plug, the receptacle having a photoelectric converter with an input end removably electrically connected to the plug portion.

In one embodiment, the plug assembly comprises a plug and a socket detachably connected with the plug, a signal amplifier is arranged in the socket, and the plug part of the plug is an output part and is detachably and electrically connected with the output end of the signal amplifier.

In one embodiment, a photoelectric converter is arranged in the socket, and the input end of the photoelectric converter is electrically connected with the output end of the signal amplifier.

In another aspect, the present invention further provides a magnetic resonance apparatus, including the receiving unit in any of the above embodiments, the plug assembly includes a plug and a socket detachably connected to the plug, and the signal amplifier is disposed on the plug or the socket. The magnetic resonance equipment also comprises a rack unit and an upper computer, wherein the rack unit is provided with a detection cavity, the rack unit comprises a support frame and a bearing plate capable of moving relative to the support frame, the support frame is arranged outside the detection cavity, and the bearing plate is fixedly provided with a socket. The upper computer is electrically connected with the socket through a second transmission cable.

The magnetic resonance equipment adopts the receiving unit, when in use, a detected person lies on the bearing plate, the induction coil is arranged at a detected position, and then the detected person is pushed into the detection cavity through the bearing plate. During detection, the detection electric signal generated by the induction coil can be transmitted into the signal amplifier for signal amplification only through the first transmission cable, and then the amplified detection electric signal is transmitted to the upper computer by the second transmission cable. In the process, the initial detection electric signal generated by the induction coil is transmitted only through the first short transmission cable, so that the loss is low, and the influence of the transmission cable on the reduction of the signal-to-noise ratio of the initial detection signal can be reduced; and then the signal is amplified by the signal amplifier and transmitted to the upper computer by the second transmission line.

Meanwhile, the signal amplifier is integrated into the plug-in assembly, so that the space of the plug-in assembly can be fully utilized; and the plug is easily dismantled, and the supporting board is easily pushed out, possesses sufficient operating space, is favorable to the change or the maintenance of signal amplifier.

The technical solution is further explained below:

in one embodiment, the plug or the socket is provided with a photoelectric converter, the input end of the photoelectric converter is electrically connected with the output end of the signal amplifier, and the output end of the photoelectric converter is electrically connected with the upper computer through a second transmission cable; the second transmission cable is an optical fiber.

In one embodiment, the induction coil is removably attached to the support plate.

In one embodiment, the magnetic resonance apparatus further includes a drag chain disposed between the support frame and the support plate, and the drag chain is connected to the second transmission cable such that one end of the second transmission cable can move along with the drag chain.

Drawings

Fig. 1 is a schematic structural diagram of a magnetic resonance apparatus shown in an embodiment;

figure 2 is a diagrammatic illustration of the use of the magnetic resonance apparatus shown in figure 1;

figure 3 is a diagrammatic illustration of the magnetic resonance apparatus of figure 1 with the receiving unit removed;

FIG. 4 is a schematic diagram of the structure of the receiving unit shown in FIG. 3;

FIG. 5 is a block diagram of a receiving unit in one embodiment;

FIG. 6 is a schematic structural diagram of a receiving unit shown in another embodiment;

FIG. 7 is a schematic structural diagram of a receiving unit shown in another embodiment;

FIG. 8 is a schematic structural diagram of a receiving unit shown in another embodiment;

figure 9 is an electrical schematic diagram of a magnetic resonance apparatus shown in one embodiment;

fig. 10 is an electrical schematic diagram of a magnetic resonance apparatus shown in another embodiment.

Description of reference numerals:

10. a receiving unit; 20. a rack unit; 22. a detection chamber; 24. a support frame; 26. a bearing plate is arranged; 30. an upper computer; 40. a second transmission cable; 50. a drag chain; 100. an induction coil; 200. a first transmission cable; 300. a plug-in assembly; 310. a signal amplifier; 320. an output section; 330. a plug; 340. a socket; 350. a photoelectric converter.

Brief description of the drawingsthe accompanying drawings, which form a part hereof, are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification, illustrate exemplary embodiments of the invention, and together with the description, serve to explain the invention and not to limit the invention.

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is further described in detail below with reference to the accompanying drawings and the detailed description. It should be understood that the detailed description and specific examples, while indicating the scope of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

The application of the magnetic resonance detection technology in the medical field has very important significance, and doctors can be assisted to judge and treat more accurately. The better the quality of the magnetic resonance imaging, the lower the cost, the more competitive the magnetic resonance apparatus. Therefore, how to improve the imaging quality and provide clearer images is a continuous pursuit of manufacturers of magnetic resonance equipment.

At present, the induction coil of the receiving unit collects detection electric signals and transmits the detection electric signals to the upper computer, and in the process of obtaining corresponding images after the processing of the upper computer, the initial detection electric signals are transmitted in a longer transmission cable to cause loss and noise, so that signal attenuation is caused, and the imaging quality of the magnetic resonance equipment is not improved.

Based on this, it is necessary to provide a receiving unit capable of reducing the influence of the transmission cable on the reduction of the signal-to-noise ratio of the initial detection signal; the method is applied to the magnetic resonance equipment, and can improve the imaging quality of the magnetic resonance equipment.

For a better understanding of the receiving unit of the invention, reference is now made to a magnetic resonance apparatus to which the receiving unit is applied.

As shown in fig. 1 to 3, in one embodiment, a magnetic resonance apparatus is provided, which includes a receiving unit 10, a gantry unit 20, and an upper computer 30.

As shown in fig. 3, 4 and 9, the receiving unit 10 includes an induction coil 100 capable of inducing and generating a detection electrical signal, a first transmission cable 200 capable of transmitting the detection electrical signal, and a plug assembly 300. The plug assembly 300 is connected to the induction coil 100 through the first transmission cable 200, and the plug assembly 300 includes a signal amplifier 310 and an output portion 320, wherein an input end of the signal amplifier 310 is electrically connected to the first transmission cable 200, and an output end of the signal amplifier 310 is electrically connected to the output portion 320. The plug assembly 300 further includes a plug 330 and a receptacle 340 detachably connected to the plug 330, and the signal amplifier 310 is disposed on the plug 330 or the receptacle 340.

In addition, the rack unit 20 is provided with a detection chamber 22, the rack unit 20 includes a support frame 24 and a support plate capable of moving relative to the support frame 24, the support frame 24 is disposed outside the detection chamber 22, and the support plate is fixedly provided with a socket 340. The upper computer 30 is electrically connected with the socket 340 through a second transmission cable 40.

The magnetic resonance apparatus employs the receiving unit 10, and when in use, a subject lies on the supporting plate, the induction coil 100 is disposed at a subject position, and then the subject is pushed into the detection chamber 22 through the supporting plate. During detection, the detection electrical signal generated by the induction coil 100 can be transmitted into the signal amplifier 310 for signal amplification only through the first transmission cable 200, and then the amplified detection electrical signal (which may or may not be converted) is transmitted to the upper computer 30 through the second transmission cable 40. In the process, the initial detection electric signal generated by the induction coil 100 is transmitted only through the shorter first transmission cable 200, so that the loss is smaller, and the influence of the transmission cable on the reduction of the signal-to-noise ratio of the initial detection signal can be reduced; and then the signal is amplified by the signal amplifier 310 and transmitted to the upper computer 30 through the second transmission line, so that compared with the prior art, the signal transmission quality can be improved, and the imaging quality of the magnetic resonance equipment can be improved.

Meanwhile, the imaging quality of the magnetic resonance equipment is improved by improving the receiving unit 10, only the plug 330 or the socket 340 is changed, not only the cost is lower, but also the modification influence on the production line of the magnetic resonance equipment is smaller, and the cost for the previous modification is also lower.

Further, it will be appreciated that integrating the signal amplifier 310 into the plug-in assembly 300 can take full advantage of the space of the plug-in assembly 300; and the plug 330 is easy to be dismantled, the bearing plate is easy to be pushed out, and the signal amplifier 310 has enough operation space, is favorable for replacement or maintenance of the signal amplifier 310, and can improve the maintenance efficiency of the magnetic resonance equipment.

It should be noted that the "induction coil 100" may be any conventional detecting element capable of being applied to magnetic resonance imaging, including but not limited to a full-volume coil, a partial-volume coil, a surface coil, an intra-body-cavity coil, a phased-array coil, etc.

In addition, the "detection electrical signal" may be generated according to the characteristics of the induction coil 100, including but not limited to a radio frequency electrical signal, as long as the imaging can be finally obtained.

Based on the above embodiments, as shown in fig. 3 and fig. 4, in an embodiment, a signal amplifier 310 is disposed in the plug 330, and the plug portion of the plug 330 is an output portion 320. Therefore, the plug 330 can be integrated with the signal amplifier 310 independently, and then the first transmission cable 200 and the induction coil 100 form an independent module, so that the technology can be realized only by modifying the plug 330, and the influence of the improved technology on the production line of the magnetic resonance equipment can be reduced. Meanwhile, the plug 330, the first transmission cable 200 or the induction coil 100 are independent modules, so that the replacement or maintenance process is more flexible, the plug can be taken out independently for maintenance, and the operation of equipment is not influenced.

In addition to the above embodiments, as shown in fig. 5 and 10, in one embodiment, an optical-to-electrical converter 350 is disposed in the plug 330, an input end of the optical-to-electrical converter 350 is electrically connected to an output end of the signal amplifier 310, and an output end of the optical-to-electrical converter 350 is electrically connected to the output portion 320. In this way, by providing the photoelectric converter 350 to convert the detection electric signal into an optical signal for transmission, the loss in the signal transmission process can be further reduced, and the imaging quality of the magnetic resonance device can be further improved.

Meanwhile, the photoelectric converter 350 is arranged on the plug 330, the technology can be realized only by modifying the plug 330, the influence on the production line of the magnetic resonance equipment caused by the improved technology can be reduced, and the later maintenance is facilitated.

Alternatively, as shown in fig. 6, in another embodiment, the plug assembly 300 includes a receptacle 340 detachably connected to the plug 330, the receptacle 340 is provided with an optical-to-electrical converter 350, and an input end of the optical-to-electrical converter 350 is detachably electrically connected to the plug portion. In this way, by providing the photoelectric converter 350 to convert the detection electric signal into an optical signal for transmission, the loss in the signal transmission process can be further reduced, and the imaging quality of the magnetic resonance device can be further improved. Meanwhile, the photoelectric converter 350 is arranged on the socket 340, the technology can be realized only by transforming the socket 340, and the influence on the production line of the magnetic resonance equipment caused by the improved technology can be reduced. And socket 340 sets up on the bearing plate, and the bearing plate is deviate from easily, also is convenient for later maintenance.

On the basis that the plugging part is any embodiment of the output part 320, optionally, the first transmission cable 200 is detachably connected to the plug 330, and the first transmission cable 200 is detachably and electrically connected to the input end of the signal amplifier 310. Thus, the plug 330 can be assembled as an independent module, is more flexible in replacement or maintenance, can be taken out alone for overhaul, and does not affect the operation of equipment.

Similarly, in one embodiment, the socket 340 is detachably fixed on the supporting plate, and the socket 340 is detachably connected to the second transmission cable 40. Therefore, the socket 340 can be assembled as an independent module, is more flexible in the replacement or maintenance process, can be taken out independently for overhauling, and does not influence the operation of equipment.

In another embodiment, as shown in fig. 7, the plug assembly 300 includes a plug 330 and a receptacle 340 detachably connected to the plug 330, the signal amplifier 310 is disposed in the receptacle 340, and the plug portion of the plug 330 is an output portion 320 (see fig. 4) and is detachably electrically connected to the output end of the signal amplifier 310. Thus, the socket 340 can be independently integrated with the signal amplifier 310, and then form an independent module with the induction coil 100 through the plug 330 and the first transmission cable 200, so that the above-mentioned technology can be realized only by transforming the socket 340, and the influence on the production line of the magnetic resonance equipment caused by the improved technology can be reduced. Meanwhile, the socket 340 is an independent module, and the socket 340 is arranged on the bearing plate, so that the bearing plate is easy to separate, and the socket 340 can be taken out independently for maintenance.

Based on the above embodiments, as shown in fig. 8 and 10, in an embodiment, the receptacle 340 is provided with the photoelectric converter 350, and an input end of the photoelectric converter 350 is electrically connected to an output end of the signal amplifier 310. In this way, by providing the photoelectric converter 350 to convert the detection electric signal into an optical signal for transmission, the loss in the signal transmission process can be further reduced, and the imaging quality of the magnetic resonance device can be further improved. Meanwhile, the photoelectric converter 350 is arranged on the socket 340, the technology can be realized only by transforming the socket 340, and the influence on the production line of the magnetic resonance equipment caused by the improved technology can be reduced.

On the basis of any one of the above embodiments of the photoelectric converter 350, specifically in this embodiment, the output end of the photoelectric converter 350 is electrically connected to the upper computer 30 through the second transmission cable 40; the second transmission cable 40 is an optical fiber. Therefore, the optical fiber is used for transmitting signals, so that the transmission rate can be improved, and the anti-interference performance can be improved.

In addition to any of the above embodiments, in one embodiment, the induction coil 100 is detachably connected to the support plate. Therefore, the induction coil 100 is detachably connected with the bearing, so that the position of the induction coil 100 cannot be easily displaced when the induction coil is used, the receiving unit 10 can be conveniently disassembled and assembled, and the receiving unit 10 of a required type can be arranged on the bearing plate according to requirements.

Based on any of the above embodiments, as shown in fig. 1 and fig. 2, in an embodiment, the magnetic resonance apparatus further includes a drag chain 50, the drag chain 50 is disposed between the support frame 24 and the support plate, and the drag chain 50 is connected to the second transmission cable 40, so that one end of the second transmission cable 40 can move along with the drag chain 50. In this manner, the second transmission cable 40 is shielded using the tow chain 50, improving the reliability of the electrical connection. Meanwhile, the drag chain 50 can be used for integrating and arranging cables, so that the appearance aesthetic feeling of the magnetic resonance equipment is improved.

As shown in fig. 4, the receiving unit 10 includes an induction coil 100 capable of inducing and generating a detection electric signal, a first transmission cable 200 capable of transmitting the detection electric signal, and a plug assembly 300. The plug assembly 300 is connected to the induction coil 100 through the first transmission cable 200, and the plug assembly 300 includes a plug 330, a signal amplifier 310 and an output portion 320, the signal amplifier 310 is disposed in the plug 330, an input end of the signal amplifier 310 is electrically connected to the first transmission cable 200, and an output end of the signal amplifier 310 is electrically connected to the output portion 320. Thus, the receiving unit 10 can be disassembled and assembled only by pulling and inserting the plug 330, which is convenient for replacement and maintenance. Meanwhile, the imaging quality of the magnetic resonance equipment is improved by improving the receiving unit 10, only the plug 330 is changed, the cost is low, the modification influence on the production line of the magnetic resonance equipment is small, and the cost for previous modification is low.

It should be noted that the "induction coil 100" may be one of the parts of the module "receiving unit 10", that is, produced modularly with "other components of the receiving unit 10"; or may be separate from or separable from the "other components of the receiving unit 10", i.e., may be integrally assembled with the "other components of the receiving unit 10" in the present apparatus.

Equivalently, the components included in the "unit", "assembly", "mechanism" and "device" of the present invention can be flexibly combined, i.e., can be produced in a modularized manner according to actual needs, so as to facilitate the modularized assembly. The division of the above components into the present invention is only one embodiment, which is convenient for reading and is not a limitation to the protection scope of the present invention, and the equivalent technical solutions of the present invention should be understood as if they include the above components and have the same function.

In the description of the present invention, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the invention and to simplify the description, and are not intended to indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and are not to be considered limiting of the invention.

Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," etc. may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through an intermediate. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to," "disposed on," "secured to," or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is perpendicular or nearly perpendicular to another element, it is desirable that the two elements are perpendicular, but some vertical error may exist due to manufacturing and assembly effects. The terms "vertical," "horizontal," "left," "right," and the like as used herein are for illustrative purposes only and do not represent the only embodiments.

The technical features of the above embodiments can be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the above embodiments are not described, but should be considered as the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only show some embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention.