阅读说明：本技术 用于磁共振的隔离装置、磁共振成像设备及其控制方法 (Isolation device for magnetic resonance, magnetic resonance imaging apparatus and control method thereof ) 是由 梁志鹏 于 2021-10-18 设计创作，主要内容包括：本发明涉及一种磁共振的隔离装置、磁共振成像设备及其控制方法,隔离装置包括缓冲部、压力传感器,缓冲部具有主空腔,主空腔被配置为用于充放充盈物质以使缓冲部呈扩张状态或收缩状态；压力传感器设置在缓冲部的正面,缓冲部的正面被配置为用于直接或间接接触目标对象,压力传感器被配置为用于获取目标对象的受压力信息,受压力信息被配置为用于作为控制扩张状态的扩张程度的根据。上述隔离装置,缓冲部可在目标对象进入设备前呈收缩状态,防止对目标对象的进入形成障碍,在目标对象进入到设备内后,通过压力传感器的辅助配合,在充气过程中采集对目标对象的压力,根据不同目标对象的体型控制缓冲部的扩张程度,以提高目标对象的舒适度。(The invention relates to an isolation device for magnetic resonance, a magnetic resonance imaging device and a control method thereof, wherein the isolation device comprises a buffer part and a pressure sensor, the buffer part is provided with a main cavity, and the main cavity is configured to be filled with filling materials so as to enable the buffer part to be in an expansion state or a contraction state; the pressure sensor is provided on a front surface of the cushioning portion, the front surface of the cushioning portion being configured to directly or indirectly contact the target object, the pressure sensor being configured to acquire pressure information of the target object, the pressure information being configured to be a function of controlling a degree of expansion of the expanded state. Above-mentioned isolating device, buffer can be the contraction state before target object gets into equipment, prevents to form the obstacle to target object's entering, and after target object entered into equipment, through pressure sensor's supplementary cooperation, gather the pressure to target object at the inflation in-process, according to the expansion degree of different target object's size control buffer to improve target object's comfort level.)

1. An isolation device for magnetic resonance, the isolation device comprising:

a cushioning portion having a main cavity configured for inflation and deflation of a filling substance to cause the cushioning portion to assume an expanded state or a contracted state;

a pressure sensor provided on a front surface of the cushioning portion, the front surface of the cushioning portion being configured to directly or indirectly contact a target object, the pressure sensor being configured to acquire pressure information of the target object, the pressure information being configured to be a function of controlling a degree of expansion of the expanded state.

2. The isolation device of claim 1, further comprising:

a substance delivery controller in communication with the main cavity, the substance delivery controller configured to charge and discharge the filling substance into the main cavity at least according to the pressure information to control the degree of expansion of the expanded state.

3. The isolation device of claim 2, wherein the substance delivery controller comprises:

a delivery pump;

a conduit having one end in communication with the delivery pump and another end in communication with the main cavity, the delivery pump being configured for delivering the filling substance through the conduit to the main cavity.

4. An isolation device as claimed in claim 1, wherein the buffer is provided with a connection structure configured for securing the buffer to an inner wall of a volume transmit coil in a magnetic resonance imaging apparatus.

5. The isolation device of claim 1, wherein the pressure sensors are plural in number, and the plural pressure sensors are arranged in a predetermined arrangement pattern on the front surface of the buffer portion.

6. The isolation device of claim 1, further comprising:

a surface pad disposed on a front surface of the cushioning portion, and the pressure sensor is located between the cushioning portion and the surface pad, the pressure sensor being configured to indirectly acquire the pressure information via the surface pad; wherein, the surface course pad is solid, perhaps, the surface course pad has the supplementary cavity, assist the cavity with main cavity intercommunication.

7. A magnetic resonance imaging apparatus, characterized by comprising:

the isolation device of any one of claims 1-6;

the isolation device is arranged on the inner wall of the volume transmitting coil.

8. A control method for a magnetic resonance imaging apparatus according to claim 7, comprising the steps of:

acquiring the information of the pressure of the target object according to the pressure sensor;

and the material conveying controller fills and discharges the filling material into the main cavity according to the information of the pressed force so as to control the expansion degree of the expansion state.

9. The control method according to claim 8, wherein a material delivery controller fills and discharges the filling material into the main cavity according to the pressure information to control the degree of expansion of the expanded state, comprising the steps of:

before the target object is subjected to an imaging operation, the substance delivery controller fills the main cavity with the filling substance to make the buffer portion assume the expanded state;

and when the pressure information reaches a preset pressure value, the material conveying controller stops filling the main cavity with the filling material.

10. The control method according to claim 9, wherein a substance delivery controller fills and discharges the filling substance into the main cavity according to the pressure information to control the degree of expansion of the expanded state, and thereafter, comprising the steps of:

after the target object is imaged, the material transfer controller discharges the filling material in the main cavity to make the buffer portion in the contracted state.

Technical Field

The invention relates to the technical field of high-field magnetic resonance imaging, in particular to an isolation device for magnetic resonance, a magnetic resonance imaging device and a control method thereof.

Background

In high-field magnetic resonance scanning, especially when the field strength is 3.0T, 5.0T or above, a higher SAR (specific absorption rate) may cause risks such as body burn to a target object (such as a human body or an animal), since the closer to an inner wall of a VTC (Volume transmitting Coil), the higher the SAR value is, the more simple and feasible method is to isolate a part of the target object close to the inner wall of the VTC for the purpose of protecting the target object.

The most common method at present is to isolate the arm, thigh and other parts of the target object which are easy to be close to the inner wall of the VTC by using various cushions, so as to reduce the safety risk, and in the actual operation process, a worker needs to perform cushion plugging operation on the target object after the target object enters the VTC, but in this way, not only a large number of accessories need to be added for performing cushion plugging, but also the manual operation can increase the workload of the worker, and the target object can be uncomfortable.

Disclosure of Invention

In view of the above, it is necessary to provide an isolation device for magnetic resonance, a magnetic resonance imaging apparatus, and a control method thereof, which solve the problems of discomfort to a target object and cumbersome operation when an operation of reducing an SAR value is performed in the related art.

The invention provides an isolation device for magnetic resonance, comprising:

a cushioning portion having a main cavity configured for inflation and deflation of a filling substance to cause the cushioning portion to assume an expanded state or a contracted state;

a pressure sensor provided on a front surface of the cushioning portion, the front surface of the cushioning portion being configured to directly or indirectly contact a target object, the pressure sensor being configured to acquire pressure information of the target object, the pressure information being configured to be a function of controlling a degree of expansion of the expanded state.

In one embodiment, the isolation device further comprises:

a substance delivery controller in communication with the main cavity, the substance delivery controller configured to charge and discharge the filling substance into the main cavity at least according to the pressure information to control the degree of expansion of the expanded state.

In one embodiment, the substance delivery controller comprises:

a delivery pump;

a conduit having one end in communication with the delivery pump and another end in communication with the main cavity, the delivery pump being configured for delivering the filling substance through the conduit to the main cavity.

In one embodiment, the buffer is provided with a connection structure configured for fixing the buffer to an inner wall of a volume transmission coil in a magnetic resonance imaging apparatus.

In one embodiment, the number of the pressure sensors is multiple, and the pressure sensors are arranged on the front surface of the buffer part according to a preset arrangement pattern.

In one embodiment, the isolation device further comprises:

a surface pad disposed on a front surface of the cushioning portion, and the pressure sensor is located between the cushioning portion and the surface pad, the pressure sensor being configured to indirectly acquire the pressure information via the surface pad; wherein, the surface course pad is solid, perhaps, the surface course pad has the supplementary cavity, assist the cavity with main cavity intercommunication.

The present invention also provides a magnetic resonance imaging apparatus comprising:

the isolation device;

the isolation device is arranged on the inner wall of the volume transmitting coil.

The invention also provides a control method based on the magnetic resonance imaging equipment, which comprises the following steps:

acquiring the information of the pressure of the target object according to the pressure sensor;

and the material conveying controller fills and discharges the filling material into the main cavity according to the information of the pressed force so as to control the expansion degree of the expansion state.

In one embodiment, the substance delivery controller fills and discharges the filling substance into the main cavity according to the information of the pressure to control the expansion degree of the expansion state, and the method includes the following steps:

before the target object is subjected to an imaging operation, the substance delivery controller fills the main cavity with the filling substance to make the buffer portion assume the expanded state;

and when the pressure information reaches a preset pressure value, the material conveying controller stops filling the main cavity with the filling material.

In one embodiment, the substance delivery controller fills and discharges the filling substance into the main cavity according to the information of the pressure to control the expansion degree of the expansion state, and then the method further includes the following steps:

after the target object is imaged, the material transfer controller discharges the filling material in the main cavity to make the buffer portion in the contracted state.

Above-mentioned an isolating device for magnetic resonance, buffer can be the contraction state before target object gets into equipment, prevents to form the obstacle to target object's entering, and in target object gets into equipment back, can gather the pressure to target object at the inflation in-process through pressure sensor's supplementary cooperation, according to the expansion degree of different target object's size control buffer to improve target object's comfort level, also reduced staff's work load simultaneously, reduced the annex of equipment.

Drawings

FIG. 1 is a schematic view of a prior art spacer mat;

fig. 2 is a schematic diagram of a back structure of an isolation device according to an embodiment of the present invention;

FIG. 3 is a schematic front view of an isolation device according to an embodiment of the present invention;

FIG. 4 is a schematic illustration of the location of an isolation location provided by one embodiment of the present invention;

FIG. 5 is a schematic view of an isolation device according to an embodiment of the present invention;

fig. 6 is a schematic structural diagram of an isolation device according to another embodiment of the present invention.

Reference numerals:

001. an isolation device; 002. a volume-emitting coil; 003. a target object; 004. an isolation location;

100. a buffer section; 200. a pressure sensor; 300. a substance delivery controller; 400. and (5) a connecting structure.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

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" and "first" 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" or "second" may explicitly or implicitly include at least one such 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" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

Referring to fig. 1, most of the conventional mats for isolating the target object from the inner wall of the volume transmitting coil are square or other similar mats, and the inside of the mats is solid, and filled with a substance having a buffering effect, such as cotton, and the like. When the volume transmitting coil is used, a worker can insert the cushion plug at a position, such as the position of the arm and the outer side of the thigh, of the target object, which is close to the inner wall of the volume transmitting coil after the target object enters the volume transmitting coil, so as to realize the isolation of the target object.

Referring to fig. 2 and 3, an embodiment of the present invention provides an isolation device 001 for magnetic resonance, the isolation device 001 includes a buffer portion 100, a pressure sensor 200, the buffer portion 100 can be in an expanded state or a contracted state, the buffer portion 100 has a main cavity configured to be filled with an inflation substance to make the buffer portion 100 in the expanded state or the contracted state, the inflation substance is a gas or a liquid, the pressure sensor 200 is disposed on a front surface of the buffer portion 100, the front surface of the buffer portion 100 is configured to be in direct or indirect contact with a target object 003, such as the front surface of the buffer portion 100 is in direct contact with the target object 003 or in indirect contact with the target object 003 through other components, to satisfy force transmission and isolation of the target object 003, the pressure sensor 200 is configured to acquire pressure information of the target object 003, the pressure information is configured to be used as a basis for controlling the degree of expansion of the expanded state. The expanded and contracted states of cushioning portion 100 are controllable and switchable, and are not two separate states that are not constant and switchable.

The main body component of the isolation device 001 is the buffer part 100 capable of expanding and contracting, the buffer part 100 can adopt structures such as an air cushion, an air bag, a water cushion and a water bag, the buffer part 100 can form a main cavity capable of filling and discharging filling materials in the buffer part 100, the main cavity can be used for filling and discharging matched filling materials, for example, when the buffer part 100 adopts the air cushion and the air bag, the filling materials can adopt gas, after the gas is filled into the main cavity of the air cushion or the air bag, the air cushion or the air bag can be filled to be in an expanded state, and after the gas is discharged, the air cushion or the air bag is switched to be in a contracted state, wherein the gas filled into the main cavity can be common air, and can also be nitrogen with more stable properties, and the like, and the buffer part is not limited herein. Similarly, when the cushioning portion 100 is a water cushion or a water bag, the filling material may be a liquid, and after the liquid is filled into the main cavity of the water cushion or the water bag, the water cushion or the water bag may be filled to be in an expanded state, and after the liquid is discharged, the water cushion or the water bag is switched to be in a contracted state, wherein the liquid filled into the main cavity may be ordinary water, or may be other non-toxic and harmless liquid, and the like, which is not limited herein.

Referring to fig. 4 and 5, the inner cavity of the volume transmitting coil 002 may form an aperture for the imaging operation of the target object 003, the target object 003 needs to enter the aperture to perform the imaging operation, and based on the expansion and contraction functions of the buffer portion 100, the proper state can be automatically matched before the target object 003 enters the aperture of the volume transmitting coil 002 and after the target object enters the aperture of the volume transmitting coil 002, because the aperture of the volume transmitting coil 002 is relatively narrow, therefore, before the target object 003 enters the aperture of the volume-emitting coil 002, the buffer part 100 can be controlled to be in a contracted state, and the contracted state can make the buffer part 100 be shrunk to a relatively small volume, even the inner space of the aperture of the volume-emitting coil 002 is not basically occupied, this can provide more movable space for entry of the target object 003, enabling easy entry of the target object 003. When the target 003 enters the aperture of the volume transmission coil 002, the buffer part 100 can be switched from the contracted state to the expanded state to increase its volume, and fill the space between the target 003 and the inner wall of the aperture of the volume transmission coil 002, such as the isolation position 004 shown in fig. 4, thereby playing the role of isolation. The target object 003 may be a living body, which may be a human or an animal such as a patient or a patient.

In the contracted state of the buffer unit 100, the buffer unit 100 in the contracted state is normally in a state substantially free from a filler, but when the buffer unit 100 is in the expanded state, the expanded state has a corresponding degree of expansion, the expanded states determined by different degrees of expansion are different, and the higher the degree of expansion, the larger the volume of the buffer unit 100, and the lower the degree of expansion, the smaller the volume of the buffer unit 100, so that, when the spatial size of the aperture of the volume emitting coil 002 is not changed, the same buffer unit 100 can be applied to the target objects 003 of different body types based on the control of the degree of expansion, and when the body type of the target object 003 is large, the degree of expansion of the buffer unit 100 can be reduced, and when the body type of the target object 003 is small, the degree of expansion of the buffer unit 100 can be increased accordingly, and the degree of expansion of the buffer unit 100 can be adjusted in accordance with the actual body type of the target object 003, and an effective isolation distance can be formed between the inner wall of the volume emitting coil 002 and the target object 003 by adjusting the isolation distance The target 003 is not pressed too much, and the target 003 is not uncomfortable.

For the determination of the body type of the object 003, the isolation device 001 employs the pressure sensor 200, the pressure sensor 200 is disposed on the front surface of the buffer part 100, when the object 003 enters the aperture of the volume emitting coil 002, the buffer part 100 starts to be filled with the filling material, so that the buffer part 100 is converted into the expanded state and the degree of expansion is continuously raised, as the buffer part 100 is continuously expanded, the front surface of the buffer part 100 contacts the isolation position 005 of the object 003 and continuously presses the object 003, at this time, the pressure sensor 200 can obtain the pressure information of the object 003, that is, measure the current pressure value, the larger the pressure value is, the larger the pressure information is, the smaller the pressure value is, the smaller the pressure information is, therefore, the pressure value (or the pressure information) can be used as the basis for controlling the degree of expansion of the expanded state, according to the preset control logic, the expansion degree of the buffer part 100 can be controlled by the pressure information to match the body type of the current target object 003, so that the target object 003 can be isolated at a larger distance through the expansion thickness of the buffer part 100, and the target object 003 is not excessively pressed, and the target object 003 is uncomfortable.

In order to ensure the sensitivity and accuracy of the acquisition of the pressure information, the number of the pressure sensors 200 may be a plurality of pressure sensors 200, the plurality of pressure sensors 200 are arranged on the front surface of the cushioning portion 100 according to a preset arrangement pattern, and the specific arrangement pattern includes any one or combination of a ring shape, a circle shape, an oval shape, a square shape, a rectangle shape and a trapezoid shape, which can be designed according to the position of the isolated target object 003 of the specific requirement, as long as the sensitive attachment is satisfied, and the pressure sensors are not limited to various arrangement forms.

In one embodiment, the isolation device 001 further comprises a surface pad disposed on the front surface of the buffer part 100, and the pressure sensor 200 is located between the buffer part 100 and the surface pad, and the pressure sensor 200 is configured to indirectly acquire the pressure information through the surface pad. In this case, the surface pad may be a portion directly contacting the target 003, that is, the front surface of the cushioning portion 100 indirectly contacts the target 003 through the surface pad, so that the force transmission and the isolation of the target 003 are satisfied, and after the surface pad is contacted with the target 003, the target 003 applies the pressure to the surface pad, and the surface pad disperses and uniformly transmits the pressure to the pressure sensor 200, so that the pressure information can be more sensitively and accurately acquired. The surface layer pad can be solid and is realized by filling cotton and other substances, and the surface layer pad can also be provided with an auxiliary cavity which is communicated with the main cavity and forms a common cavity along with the main cavity, so that the surface layer pad can expand and contract.

Therefore, the isolation device 001 simplifies the overall configuration of the magnetic resonance imaging apparatus, does not need to be provided with other additional various cushions for protection, does not need a technician to perform the operation of plugging the cushions, the buffer part 100 can be in a contracted state before the target object 003 enters the apparatus, prevents the target object 003 from entering into obstacles, can collect the pressure on the target object 003 in the inflation process through the auxiliary cooperation of the pressure sensor 200 after the target object 003 enters the apparatus, and controls the expansion degree of the buffer part 100 according to the body types of different target objects 003, so as to improve the comfort of the target object 003, reduce the workload of the operator, and reduce the accessories of the apparatus, namely the number of cushions.

Referring to fig. 6, the isolation device 001 further comprises a substance delivery controller 300, the substance delivery controller 300 is in communication with the main cavity, and the substance delivery controller 300 is configured to charge and discharge the filling substance into the main cavity according to at least the pressure information to control the degree of expansion of the expanded state. The material delivery controller 300 can realize automatic and controllable charging and discharging of the filling material, and under the preset control logic, according to the data provided by the pressure information, the material delivery controller 300 can automatically control the charging and discharging of the filling material and control the charging and discharging amount of the filling material in real time, so that the buffer part 100 can automatically and controllably adjust the expansion degree of the buffer part 100 and the conversion of the buffer part 100 between the expansion state and the contraction state, and the current body type of the target object 003 is automatically matched. For example, when the pressure information reaches the set value, the material delivery controller 300 stops filling with the filling material, and when the imaging scan is finished, the material delivery controller 300 releases the filling material, and the whole process is controlled by the material delivery controller 300, so that the intelligent operation is realized.

The substance transfer controller 300 may employ various means depending on the substance to be transferred, for example, an air pump when the substance to be transferred is gas, and a water pump when the substance to be transferred is liquid. The substance delivery controller 300 includes a delivery pump, such as an air pump or a water pump, and further includes a pipe, one end of which is communicated with the delivery pump, and the other end of which is communicated with the side surface or the back surface of the cushioning portion 100 at another suitable position and is further communicated with the main cavity, and the delivery pump is configured to deliver the filling substance to the main cavity through the pipe, wherein the back surface of the cushioning portion 100 is opposite to the front surface of the cushioning portion 100. The pipeline can adopt structures such as water pipe, trachea, and the pipeline is connected at the back of buffer 100, can prevent that target object 003 from getting into volume transmitting coil 002 aperture and oppressing the pipeline when contacting with the front of buffer 100, leads to filling and discharging slowly or malfunctioning of filling material, and the whole process need not the technician operation, has simplified technician's work load greatly. The material delivery controller 300 may be located in a plant room or on the service side of the mri apparatus, and the tubing may be hidden within the mri apparatus housing and then connected to the delivery pump.

The overall external dimension of the buffer part 100 may be designed according to the specific location of the target object 003 to be isolated, and the buffer part 100 may be integrated with the inner wall of the aperture of the volume transmitting coil 002. in one embodiment, the back surface of the buffer part 100 is provided with a connecting structure 400, the connecting structure 400 is configured to fix the buffer part 100 to the inner wall of the volume transmitting coil 002, and the volume transmitting coil 002 belongs to a component in a magnetic resonance imaging apparatus, wherein the back surface of the buffer part 100 is opposite to the front surface of the buffer part 100. Connection structure 400 can be for forms such as magic subsides, buckle, and when the back of buffer 100 was integrated with the installation of volume transmitting coil 002 inner wall, the pipeline can be through realizing the assembly at the fluting of volume transmitting coil 002.

In one embodiment, the present invention further provides a magnetic resonance imaging apparatus, including the isolation device 001 and the volume transmission coil 002, wherein the isolation device 001 is disposed on an inner wall of the volume transmission coil 002. At this time, the worker may manually charge and discharge the buffer unit 100, or manually operate the substance transfer controller 300 to charge and discharge the buffer unit 100. In addition, the filling and discharging of the filling material in the main cavity of the buffer unit 100 may be controlled not only manually but also automatically based on the automatic expansion and contraction of the buffer unit 100 in the spacer 001, which is not limited herein.

The invention also provides a control method based on the magnetic resonance imaging equipment, which comprises the following steps: acquiring the information of the pressure of the target object 003 according to the pressure sensor 200; the substance delivery controller fills the main cavity with the filling substance according to the pressure information to control the degree of expansion of the expanded state, for example, before the imaging operation is performed on the target object 003, the substance delivery controller 300 fills the main cavity with the filling substance, such as an inflation or liquid filling body, to make the buffer portion 100 assume the expanded state, and when the pressure information reaches a preset pressure value, the substance delivery controller 300 stops filling the main cavity with the filling substance, which is control of switching the buffer portion 100 from the contracted state to the expanded state and control of the degree of expansion. After the imaging operation is completed on the target object 003, the substance transfer controller 300 discharges the filling substance, such as the discharge gas or the discharge liquid, to the main cavity to cause the cushioning portion 100 to assume the contracted state, which is control for switching the cushioning portion 100 from the expanded state to the contracted state. Since the specific structure, functional principle and technical effect of the isolation device 001 are described in detail in the foregoing, no further description is given here, and the specific charging and discharging operations can be referred to in the foregoing.

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

The above-mentioned embodiments only express several 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. Therefore, the protection scope of the present patent shall be subject to the appended claims.