Gradient coil structure of magnetic resonance equipment and strain detection method and device

Abstract

According to the gradient coil structure of the magnetic resonance equipment and the strain detection method and device provided by the embodiment of the invention, the strain reference information and the temperature reference information in each preset position are detected through the sensor group in the gradient coil structure of the magnetic resonance equipment; therefore, the strain reference information can be corrected based on the temperature reference information, so that the influence of the temperature on the strain is reduced, and the strain of each preset position can be accurately detected.

Description

Technical Field

[0001] The present application belongs to the technical field of magnetic resonance equipment, and in particular, relates to a gradient coil structure, strain detection and device of a magnetic resonance equipment. Background Art

[0002] Magnetic resonance (MR) equipment imaging relies on gradient coils to generate gradient coil alternating magnetic fields in different directions within the aperture, which is achieved by relying on sequence signals in the gradient coils, i.e., alternating current signals. The gradient coil is similar in shape to a spiral coil and is placed in the middle of a magnet. When an alternating current is applied to the gradient coil, the gradient coil will be subjected to the alternating Lorentz magnetic force, which will not only cause the gradient coil to vibrate, but also produce a certain deformation, so that the gradient coil is always subjected to the alternating load during operation. Due to the alternating load, the gradient coil has safety issues. Therefore, it is necessary to detect the strain of the gradient coil to provide important data support for reliability judgment, gradient coil fatigue life prediction, and evaluation of the correctness of simulation calculations of the gradient coil structure of the MR device in the subsequent service process. The method of strain detection of the gradient coil structure in the related art has the problem of inaccurate detection results. Summary of the invention

[0003] Based on this, the embodiments of the present application provide a model of a gradient coil structure of a magnetic resonance device, a strain detection method and a device, which can more accurately detect the strain in the gradient coil structure.

[0004] In a first aspect, an embodiment of the present application provides a gradient coil structure of a magnetic resonance device, comprising: a gradient coil body, and at least one sensor group, each sensor group being arranged at a preset position on the gradient coil body, each sensor group comprising: a strain sensor and a temperature sensor, the strain sensor in each sensor group being used to detect strain reference information of a corresponding preset position, and the temperature sensor in each sensor group being used to detect temperature reference information of a corresponding preset position.

[0005] In some implementations, the strain sensor includes: a fiber Bragg grating strain sensor; the temperature sensor includes: a fiber Bragg grating temperature sensor, the fiber Bragg grating strain sensor is connected to a fiber Bragg grating regulator via a first optical fiber, the fiber Bragg grating temperature sensor is connected to the grating regulator via a second optical fiber, or the fiber Bragg grating strain sensor and the fiber Bragg grating temperature sensor are connected to the fiber Bragg grating regulator via a third optical fiber.

[0006] In some implementations, the preset position includes: a preset position in a circumferential direction of the gradient coil body and / or a preset position in an axial direction of the gradient coil body.

[0007] In some implementations, the gradient coil structure of the magnetic resonance device further includes: a non-metallic packaging device, through which the fiber Bragg grating temperature sensor is packaged in the gradient coil body, the non-metallic packaging device has a cavity and a small hole connected to the cavity, the optical fiber of the fiber Bragg grating temperature sensor passes through the small hole, one end of the grating area of ​​the fiber Bragg grating temperature sensor is fixed in the small hole, and the other end of the grating area of ​​the fiber Bragg grating temperature sensor is arranged in the cavity.

[0008] In some implementations, the non-metallic packaging device includes: a ceramic tube.

[0009] In a second aspect, an embodiment of the present application provides a strain detection method, which is applied to the gradient coil structure of the magnetic resonance device described in any one of the above items, comprising:

[0010] Acquire temperature reference information of a preset position acquired by a temperature sensor in the sensor group, and acquire strain reference information of the preset position acquired by a strain sensor in the sensor group;

[0011] The strain reference information is corrected based on the temperature reference information to determine target strain reference information of the preset position corresponding to the target sensor group under the influence of strain.

[0012] In some embodiments, the temperature reference information includes: a first central wavelength offset; the strain reference information includes: a second central wavelength offset; and the step of correcting the strain reference information based on the temperature reference information to determine the target strain reference information under the influence of the strain at the preset position includes:

[0013] The target strain reference information of the preset position under the influence of strain is determined by subtracting the first central wavelength offset from the second central wavelength offset.

[0014] In some embodiments, the method further comprises:

[0015] determining the strain at the preset position based on the strain reference information;

[0016] The strain at the preset position is output.

[0017] In a third aspect, an embodiment of the present application provides a strain detection device, comprising:

[0018] An acquisition module, used to acquire temperature reference information of a preset position collected by a temperature sensor in the sensor group, and strain reference information of the preset position collected by a strain sensor in the sensor group;

[0019] The correction module is used to correct the strain reference information based on the temperature reference information to determine the target strain reference information of the preset position corresponding to the sensor group under the influence of strain.

[0020] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements any of the above-described methods when executing the computer program.

[0021] In a fifth aspect, an embodiment of the present application provides a computer-readable storage medium, wherein the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, any of the methods described above is implemented.

[0022] In a sixth aspect, an embodiment of the present application provides a computer program product, which, when executed on a terminal device, enables the electronic device to execute any of the methods described above.

[0023] In a seventh aspect, an embodiment of the present application provides a detection system, comprising: the gradient coil structure of the magnetic resonance device described in the first aspect, a fiber grating regulator and the electronic device described in the fourth aspect, wherein the fiber grating regulator is connected to the fiber grating strain sensor and the fiber grating temperature sensor in the gradient coil structure of the magnetic resonance device via optical fibers, and the electronic device is connected to the fiber grating regulator.

[0024] An embodiment of the present application provides a gradient coil structure of a magnetic resonance device, which detects strain reference information and temperature reference information in each preset position by setting a sensor group in the gradient coil structure of the magnetic resonance device, so that the strain reference information can be corrected based on the temperature reference information, thereby reducing the influence of temperature on strain, so that the strain at each preset position can be detected more accurately.

[0025] It can be understood that the beneficial effects of the second to seventh aspects mentioned above can be found in the relevant description of the first aspect mentioned above, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0027] Figure 1A schematic structural diagram of a gradient coil structure of a magnetic resonance device provided in an embodiment of the present application;

[0028] Figure 2 A schematic diagram of a non-metal packaging device provided in an embodiment of the present application;

[0029] Figure 3 A schematic diagram of the structure of a detection system provided in an embodiment of the present application;

[0030] Figure 4 A schematic diagram of a strain detection method provided in an embodiment of the present application;

[0031] Figure 5 A schematic structural diagram of a strain detection device provided in an embodiment of the present application;

[0032] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application.

[0033] In the drawings, the same reference numerals are used for the same components, and the drawings are not drawn to scale. DETAILED DESCRIPTION

[0034] In the following description, specific details such as specific system structures, technologies, etc. are provided for the purpose of illustration rather than limitation, so as to provide a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the present application may also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the present application.

[0035] It should be understood that when used in the present specification and the appended claims, the term "comprising" indicates the presence of described features, wholes, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and / or combinations thereof.

[0036] It should also be understood that the term “and / or” used in the specification and appended claims refers to any and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0037] As used in the specification of this application and the appended claims, the term "if" can be interpreted as "when" or "uponce" or "in response to determining" or "in response to detecting" depending on the context. Similarly, the phrases "if it is determined" or "if it is detected" can be interpreted as meaning "uponce it is determined" or "in response to determining" or "uponce detected" or "in response to detecting" depending on the context.

[0038] In addition, in the description of the present application specification and the appended claims, the terms "first", "second", "third", etc. are only used to distinguish the descriptions and cannot be understood as indicating or implying relative importance.

[0039] References to "one embodiment" or "some embodiments" etc. described in the specification of this application mean that one or more embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Therefore, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in this specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0040] Before introducing the embodiments of the present application, a brief introduction to the related art and the problems in the related art is given:

[0041] Magnetic resonance imaging equipment relies on gradient coils to generate gradient coil alternating magnetic fields in different directions within the aperture, which is achieved by relying on sequence signals in the gradient coils, that is, alternating current signals. The gradient coil is similar in shape to a spiral coil and is placed in the middle of a magnet. When an alternating current is applied to the gradient coil, the gradient coil will be subjected to alternating Lorentz magnetic forces. The alternating Lorentz magnetic forces will not only cause the gradient coils to vibrate, but also produce certain deformations, so that the gradient coils are always subjected to alternating loads during operation, which causes safety issues for the gradient coils. The existing safety issues may include: static damage, fatigue damage, thermal fatigue, etc. Among them, static damage refers to: when the sequence signal intensity is too large or the gradient coil intensity is insufficient, the local stress of the gradient coil is too large and fails. Fatigue damage refers to: the gradient coil material gradually accumulates damage under repeated loads, eventually leading to local failure. Fatigue damage usually has no external macroscopic signs of significant plastic deformation, which indicates that fatigue damage is more dangerous and difficult to detect before complete failure. Thermal fatigue is: the alternating current in the gradient coil will cause the internal temperature field of the gradient coil to vary with time. There are combinations of materials with different thermal expansion coefficients in the gradient coil, which is prone to thermal fatigue. Due to the effect of alternating loads, it is necessary to detect the strain of the gradient coil to provide important data support for reliability judgment of the MR gradient coil structure in the subsequent service process, gradient coil fatigue life prediction, and evaluation of the correctness of simulation calculations. The method of strain detection of gradient coils in related technologies does not consider the influence of temperature, resulting in inaccurate detection results.

[0042] Based on technical issues related to the technology, Figure 1 A schematic diagram of a gradient coil structure of a magnetic resonance device provided in an embodiment of the present application is shown in FIG. Figure 1As shown, Figure 1 Only one sensor group is taken as an example, including: a gradient coil body 100, at least one sensor group, each sensor group is arranged at a preset position on the gradient coil body, each sensor group includes: at least one strain sensor 200 and at least one temperature sensor 300, the strain sensor 200 in each sensor group is used to detect strain reference information at the corresponding preset position, and the temperature sensor 300 in each sensor group is used to detect temperature reference information at the corresponding preset position.

[0043] In the embodiment of the present application, the gradient coil body may be a gradient coil structure, which is an important component of the magnetic resonance imaging system, and is used to generate a spatially varying magnetic field gradient coil to achieve signal acquisition and imaging at different positions. In the embodiment of the present application, the material of the gradient coil body is mainly epoxy resin, which includes complex coils, water pipes and other structures, and the coils are arranged in a geometric shape formed by the epoxy resin. The coils may be copper coils, which are quickly energized during the magnetic resonance scanning process to generate the required magnetic field changes.

[0044] At least one sensor group may be multiple. For example, if there are N sensor groups, then N sensor groups are set at N preset positions of the gradient coil body, and each sensor group corresponds to a preset position on the gradient coil body. That is, one sensor group is used to detect temperature reference information and strain reference information of a preset position. In the embodiment of the present application, for the strain sensor and temperature sensor in each sensor group, the setting distance on the gradient coil body can be less than a distance threshold. The distance threshold can be configured, and by limiting the distance threshold, one sensor group can be able to detect strain reference information and temperature reference information in a preset position.

[0045] In the embodiment of the present application, the strain sensor includes: a fiber Bragg grating strain sensor, and the temperature sensor includes: a fiber Bragg grating temperature sensor.

[0046] In the embodiment of the present application, the fiber Bragg grating strain sensor is directly embedded in the epoxy resin, and the fiber Bragg grating temperature sensor can be embedded in the epoxy resin after being packaged by a non-metal packaging device. When embedding the sensor, it is necessary to perform special packaging treatment on the embedded fiber Bragg grating sensor to avoid damage during the pre-embedding process. The non-metal device can be a device with a thermal conductivity greater than a thermal conductivity threshold, that is, the non-metal device has good thermal conductivity.

[0047] In the embodiment of the present application, the preset position may be a position that can be used to detect strain information in the circumferential direction of the gradient coil body and / or a position that can be used to detect strain information in the axial direction of the gradient coil body.

[0048] In the embodiment of the present application, the preset position may be a position where the strain or temperature changes greatly, and the position may be determined by simulation technology. For different products, the arrangement mode, arrangement position and number of arranged sensor groups may be different.

[0049] In the embodiment of the present application, the fiber grating sensor is a sensor based on fiber optic technology, which uses the grating structure in the optical fiber to modulate the wavelength of light, thereby realizing the measurement of physical quantities. In the fiber grating sensor, when the external physical quantity (such as strain, temperature, etc.) changes, it will cause the refractive index or grating pitch of the fiber grating to change, thereby causing the central wavelength of the reflected light to shift. There is a certain relationship between the offset of this central wavelength and the change of the external physical quantity, so the change of the external physical quantity can be indirectly measured by measuring the offset of the central wavelength. For the fiber grating strain sensor, when the gradient coil body is subjected to external force, strain will be generated. This strain will cause the grating pitch of the fiber grating to change, thereby causing the central wavelength of the reflected light to shift. There is a certain relationship between this offset (i.e., the second central wavelength offset) and the strain, so the strain reference information can be obtained by measuring this offset.

[0050] Similarly, for a fiber Bragg grating temperature sensor, when the temperature of the gradient coil body or its surrounding environment changes, it will cause thermal expansion or thermo-optical effect of the fiber Bragg grating, thereby causing the center wavelength of the reflected light to shift. There is also a certain relationship between this offset (i.e., the first center wavelength offset) and the temperature change, so the temperature reference information can be obtained by measuring this offset. Therefore, the strain reference information can be the second center wavelength offset, and the temperature reference information can be the first center wavelength offset.

[0051] In the embodiment of the present application, the strain reference information is acquired by a fiber Bragg grating strain sensor under the influence of both temperature and strain, and the temperature reference information is acquired by a fiber Bragg grating temperature sensor under the influence of temperature.

[0052] In the embodiment of the present application, the temperature reference information is used to correct the strain reference information.

[0053] The gradient coil structure of the magnetic resonance device provided in the embodiment of the present application is such that each sensor group is set at a preset position on the gradient coil body, and each sensor group includes: a strain sensor and a temperature sensor. The strain sensor in each sensor group is used to detect the strain reference information of the corresponding preset position, and the temperature sensor in each sensor group is used to detect the temperature reference information of the corresponding preset position. The temperature reference information and strain reference information of a preset position can be detected, so that the strain reference information can be corrected based on the temperature reference information, thereby improving the strain detection accuracy.

[0054] In some embodiments, the strain sensor includes: a fiber Bragg grating strain sensor, the temperature sensor includes: a fiber Bragg grating temperature sensor, the fiber Bragg grating strain sensor is connected to the fiber Bragg grating regulator via a first optical fiber, the fiber Bragg grating temperature sensor is connected to the fiber Bragg grating regulator via a second optical fiber, or the fiber Bragg grating strain sensor and the fiber Bragg grating temperature sensor are connected to the fiber Bragg grating regulator via a third optical fiber.

[0055] Continue to see Figure 1 The fiber Bragg grating strain sensor and the fiber Bragg grating temperature sensor are connected to the fiber Bragg grating regulator through a third optical fiber 400.

[0056] In the embodiment of the present application, the production and curing process of the gradient coil will experience special environments such as vacuum and high temperature, and the gradient coil will also exist in high magnetic fields and alternating electric fields when working, which makes the types of sensors that can meet the test requirements very limited. In addition, fiber Bragg grating strain sensors and fiber Bragg grating temperature sensors have the characteristics of high precision and strong anti-interference ability, and are suitable for high-precision monitoring in magnetic resonance imaging equipment. Therefore, in the embodiment of the present application, fiber Bragg grating strain sensors and fiber Bragg grating temperature sensors are used.

[0057] In the embodiment of the present application, when the fiber Bragg grating strain sensor is connected to the fiber Bragg grating regulator through the first optical fiber, and the fiber Bragg grating temperature sensor is connected to the grating regulator through the second optical fiber, the two sensors are independent of each other in signal transmission and do not interfere with each other. When one of the sensors fails or needs maintenance, it will not affect the normal operation of the other sensor, thereby improving the reliability and flexibility of the system.

[0058] In the embodiment of the present application, when the fiber Bragg grating strain sensor and the fiber Bragg grating temperature sensor are connected to the fiber Bragg grating regulator through the third optical fiber, the wiring can be simplified and the data of multiple sensors can be processed centrally.

[0059] In the embodiment of the present application, different types of fiber grating strings can be customized according to the size structure of the gradient coil to realize temperature and strain acquisition on the same optical fiber at the same time.

[0060] In some embodiments, the preset position includes: a preset position in the circumferential direction of the gradient coil body and / or a preset position in the axial direction of the gradient coil body.

[0061] In the embodiment of the present application, the preset position can be confirmed by the structure of the gradient coil and the finite element simulation technology. After the position is confirmed, each sensor group can be pre-buried in the corresponding preset position when manufacturing the gradient coil structure. The axial direction can also be called the circumferential direction. The circumferential preset position refers to a specific position in the circumferential direction of the gradient coil body. By setting the sensor at the circumferential preset position, the strain and temperature changes of the gradient coil in the circumferential direction can be monitored. The axial preset position refers to a specific position in the axial direction (i.e., the length direction) of the gradient coil body. By setting the sensor at the axial preset position, the strain and temperature changes of the gradient coil in the axial direction can be monitored. By setting the sensor at the circumferential and / or axial preset positions of the gradient coil body, comprehensive monitoring of the strain and temperature changes of the gradient coil can be achieved. For the gradient coil structure, the strain is mainly reflected in the circumferential and axial directions, and the fiber Bragg grating test strain also has a strong directionality, and can only detect the strain value in the length direction, so it needs to be pre-buried strictly in the axial and circumferential directions. The main basis is to arrange it at the position with large strain gradient and temperature gradient. For different versions of products, the arrangement method, arrangement position and number of arranged sensors will be slightly different.

[0062] In some embodiments, the gradient coil structure of the magnetic resonance device further includes: a non-metal packaging device, Figure 2 A schematic diagram of a non-metal packaging device provided in an embodiment of the present application is shown in FIG. Figure 2 As shown, the fiber Bragg grating temperature sensor is packaged in the gradient coil body through a non-metallic packaging device 500. The non-metallic packaging device 500 has a cavity and a small hole connected to the cavity. The optical fiber of the fiber Bragg grating temperature sensor passes through the small hole. One end of the grating area 700 of the fiber Bragg grating temperature sensor is fixed in the small hole, and the other end of the grating area of ​​the fiber Bragg grating temperature sensor is set in the cavity.

[0063] In the embodiment of the present application, when the gradient coil is working, a high-frequency alternating current is passed through the internal coil, which will generate a changing Lorentz magnetic force, and a changing temperature field will also appear around the coil, which requires temperature compensation during the strain test. Due to the particularity of the MR device, the sensor packaging for temperature compensation cannot use metal materials, because metal materials have special electromagnetic properties in the magnetic field and are prone to interfere with the magnetic field of the magnetic resonance device. Metal packaging may introduce additional magnetic field noise, affecting the clarity and accuracy of magnetic resonance imaging. Metal packaging may also cause uneven magnetic field distribution, further affecting the imaging quality. Non-metal packaging materials usually have lower electromagnetic interference and will not have a significant impact on the magnetic field of the magnetic resonance device. Therefore, a specially customized non-metal packaging device is used to package the fiber grating temperature sensor.

[0064] In the embodiment of the present application, in order to achieve accurate temperature measurement, the non-metallic packaging device needs to have good thermal conductivity.

[0065] In the embodiment of the present application, the non-metal packaging device may be made of non-metallic materials, and the non-metallic materials may include: ceramics and the like.

[0066] In some embodiments, the non-metallic packaging device includes: a ceramic tube, a cavity is provided inside the ceramic tube, a small hole is left at one end that can just pass the optical fiber of the fiber Bragg grating temperature sensor, the fiber Bragg grating temperature sensor is completely placed inside the ceramic tube through the small hole, and then fixed at the small hole by high-temperature glue, so that the fiber Bragg grating temperature sensor is fixed at one end and free at the other end inside the ceramic package. In some embodiments, the optical fiber outlet is protected by a heat shrink tube.

[0067] In the embodiment of the present application, by making the fiber Bragg grating temperature sensor in a state where one end is fixed and the other end is free inside the ceramic package, the free end can be freely extended and retracted with temperature changes. Since the free end can move freely with temperature changes, the grating pitch of the fiber Bragg grating will also change accordingly, causing the central wavelength of the reflected light to shift, thereby achieving the measurement of temperature reference information. The design of fixing one end can limit the excessive movement of the fiber Bragg grating when the temperature changes.

[0068] The structure provided by the embodiment of the present application can significantly reduce the interference of the grating pitch change caused by external strain on the temperature measurement because one end of the grating area is fixed and the other end is set in the cavity to move relatively freely. This enables the fiber Bragg grating temperature sensor to more accurately reflect the actual temperature change without being affected by the strain.

[0069] Based on the aforementioned gradient coil structure of the magnetic resonance device, the embodiment of the present application provides a strain detection method that can be applied to electronic devices such as mobile phones, tablet computers, wearable devices, vehicle-mounted devices, augmented reality (AR) / virtual reality (VR) devices, laptops, ultra-mobile personal computers (UMPC), netbooks, personal digital assistants (PDA), etc. The embodiment of the present application does not impose any restrictions on the specific type of electronic devices. Figure 3 A schematic diagram of a detection system provided in an embodiment of the present application is shown in FIG. Figure 3As shown, the detection system includes: a gradient coil structure of a magnetic resonance device (such as the gradient in the figure), a fiber Bragg grating regulator and an electronic device. The electronic device can be a PC end, and a software program is installed in the PC end. The fiber Bragg grating regulator is connected to the fiber Bragg grating strain sensor and the fiber Bragg grating temperature sensor in the gradient coil structure of the magnetic resonance device through optical fibers, and the electronic device is connected to the fiber Bragg grating regulator.

[0070] In the embodiment of the present application, the connection between the electronic device and the fiber grating regulator can be a wired connection or a wireless connection.

[0071] In the embodiment of the present application, for strain testing, the sampling rate of the fiber Bragg grating regulator needs to match the dynamic frequency range being analyzed. During testing, the fiber Bragg grating sensor and the fiber Bragg grating strain sensor are located in the MR examination room, and the fiber Bragg grating regulator and the electronic equipment are located outside the examination room.

[0072] Based on the aforementioned detection system, the present application embodiment provides a strain detection method. Figure 4 A flow chart of a strain detection method provided in an embodiment of the present application is shown in FIG. Figure 4 As shown, the method includes:

[0073] Step S101, obtaining temperature reference information of a preset position collected by a temperature sensor in a sensor group, and obtaining strain reference information of the preset position collected by a strain sensor in the sensor group.

[0074] In the embodiment of the present application, the sensor group may be any sensor group. After the temperature sensor collects the temperature reference information, it may send the temperature reference information to the electronic device, so that the electronic device acquires the temperature reference information. After the strain sensor acquires the strain reference information, it may send the strain reference information to the electronic device, so that the electronic device acquires the strain reference information.

[0075] Step S102: correcting the strain reference information based on the temperature reference information to determine target strain reference information under the influence of strain at the preset position corresponding to the target sensor group.

[0076] In the embodiment of the present application, since temperature changes will affect the strain sensor, the strain reference information must be corrected according to the temperature reference information. A correction coefficient or a mathematical model can be applied to adjust the strain reference information to eliminate the influence of temperature on the strain reference information.

[0077] In the embodiment of the present application, the target strain reference information may refer to more accurate strain data obtained by correction after considering the temperature effect. The target strain reference information can more truly reflect the strain of the object under specific conditions.

[0078] The method provided in the embodiment of the present application obtains the temperature reference information of the preset position collected by the temperature sensor in the sensor group, and obtains the strain reference information of the preset position collected by the strain sensor in the sensor group; the strain reference information is corrected based on the temperature reference information, and the target strain reference information of the preset position corresponding to the sensor group under the influence of strain is determined, thereby reducing the influence of temperature on strain, so that the strain of each preset position can be detected more accurately.

[0079] In some embodiments, the strain sensor comprises a fiber Bragg grating strain sensor, the temperature sensor comprises a fiber Bragg grating temperature sensor, the temperature reference information comprises a first central wavelength offset, and the strain reference information comprises a second central wavelength offset.

[0080] In the embodiment of the present application, the principle of the fiber Bragg grating sensor can be simply explained as follows: based on the periodic modulation of the refractive index of the core in the optical fiber, when a beam of light enters the fiber Bragg grating sensor, only the light waves whose wavelengths meet the Bragg condition will be reflected, and the center wavelength value of the fiber Bragg grating sensor reflection spectrum can be obtained by measuring the relative light intensity of the reflected signal. The external temperature and stress cause the center wavelength of the fiber Bragg grating to shift by affecting the effective refractive index and grating period of the fiber Bragg grating. Among them, the effect of temperature on the center wavelength of the fiber Bragg grating reflection spectrum is mainly due to the thermo-optical effect and thermal expansion effect of the optical fiber material, that is, the change in temperature will cause the effective refractive index of the optical fiber core and the period of the grating to change. When only considering the effect of temperature, the center wavelength offset of the fiber Bragg grating when it is affected by temperature is:

[0081]

[0082] In the formula, λ B is the central wavelength of the fiber Bragg grating sensor, and the sum of α and β is the temperature sensitivity coefficient of the fiber Bragg grating sensor. Once the grating is written, the sensitivity of the fiber Bragg grating sensor to temperature is basically determined to be a constant value. The central wavelength offset has a good linear relationship with the temperature change.

[0083] Strain is also one of the important factors that affect the drift of the center wavelength of the fiber Bragg grating. Whether the fiber is squeezed or stretched during operation, it will directly cause the grating period to change, and the elastic-optical effect of the fiber material will also change the effective refractive index of the fiber core. Both of these changes will cause the center wavelength of the grating reflection spectrum to drift. Without considering the effect of temperature on the fiber Bragg grating, the effect of the axial strain on the center wavelength of the fiber Bragg grating is:

[0084]

[0085] Where P e is the effective elastic-optic coefficient of the fiber Bragg grating, which is a constant related only to the material coefficient; Δε is the axial strain of the fiber Bragg grating. Therefore, the center wavelength of the reflected wavelength also has a good linear relationship with the strain. By demodulating the center wavelength offset of the fiber Bragg grating, the changes in the external temperature and strain can be inferred. Other physical quantities (such as pressure and displacement, etc.) can be calculated by demodulating the offset of the center wavelength. In practical applications, the external temperature and strain will act on the fiber Bragg grating together, and the period length and refractive index of the grating will change with these two factors. According to the above analysis, the offset of the center wavelength of the reflected light of the fiber Bragg grating has a good linear relationship with both temperature and strain. From the superposition, it can be seen that when the two act together on the same section of the grating, the dependence of the center wavelength offset on strain and temperature can be described as:

[0086]

[0087] This situation is also called the temperature-strain cross-sensitivity of fiber Bragg grating in engineering. The MR gradient coil is in a typical temperature-stress cross-sensitivity environment when it is working. When the gradient coil is working, a high-frequency alternating current passes through the internal coil, which will produce a changing Lorentz magnetic force, and a changing temperature field will also appear around the coil, which requires temperature compensation during the strain test. Since the strain sensor used for strain testing is directly buried in the epoxy resin, the central wavelength offset collected is the result of the combined effect of temperature and strain, so it needs to be corrected.

[0088] In some embodiments, the modifying the strain reference information based on the temperature reference information to determine the target strain reference information of the preset position under the influence of the strain includes:

[0089] The target strain reference information of the preset position under the influence of strain may be determined by subtracting the first central wavelength offset from the second central wavelength offset.

[0090] In the embodiment of the present application, by subtracting the first central wavelength offset from the second central wavelength offset, the central wavelength offset caused only by strain, i.e., the target strain reference information, can be obtained. This step is actually to separate the part caused by temperature change from the total offset, thereby obtaining the part caused by strain.

[0091] In some embodiments, after step S102, the method may further include:

[0092] Step S103: determining the strain of the preset position corresponding to the target sensor group based on the target strain reference information.

[0093] After the target strain reference information is determined, the strain at the preset position corresponding to the target sensor group can be determined by the target strain reference information. In the embodiment of the present application, after the target strain reference information is determined, that is, the center wavelength drift amount, the strain can be calculated by formula (2).

[0094] Step S104, outputting the strain of the preset position corresponding to the target sensor group.

[0095] In the embodiment of the present application, the strain may be output through a display screen, or may be output through an email or a message.

[0096] The method provided in the embodiment of the present application can timely discover potential problems in the structure, such as cracks, fatigue, etc., by calculating strain and outputting strain.

[0097] According to the aforementioned embodiments, the embodiments of the present application provide a strain detection device, and the modules included in the device, as well as the units included in the modules, can be implemented by a processor in a computer device; of course, they can also be implemented by a specific logic circuit; in the implementation process, the processor can be a central processing unit (CPU, Central Processing Unit), a microprocessor (MPU, Microprocessor Unit), a digital signal processor (DSP, Digital Signal Processing) or a field programmable gate array (FPGA, Field Programmable Gate Array), etc.

[0098] The present application embodiment provides a strain detection device, Figure 5 A schematic diagram of a strain detection device provided in an embodiment of the present application is shown in FIG. Figure 5 As shown, the strain detection device 50 includes:

[0099] An acquisition module 51 is used to acquire temperature reference information of a preset position acquired by a temperature sensor, and acquire strain reference information of the preset position acquired by a strain sensor;

[0100] The correction module 52 is used to correct the strain reference information based on the temperature reference information to determine the target strain reference information of the preset position under the influence of the strain.

[0101] In some embodiments, the temperature reference information includes: a first central wavelength offset, the strain reference information includes: a second central wavelength offset, and the correcting the strain reference information based on the temperature reference information to determine the target strain reference information of the preset position under the influence of the strain includes:

[0102] The target strain reference information of the preset position under the influence of strain is determined by subtracting the first central wavelength offset from the second central wavelength offset.

[0103] In some embodiments, the strain detection device further comprises:

[0104] A calculation module, used for calculating the strain of the preset position based on the target strain reference information;

[0105] The output module is used to output the strain at the preset position.

[0106] It should be noted that the information interaction, execution process, etc. between the above-mentioned devices / units are based on the same concept as the method embodiment of the present application. Their specific functions and technical effects can be found in the method embodiment part and will not be repeated here.

[0107] In addition, the positioning device may be a software unit, a hardware unit, or a unit combining software and hardware, or may be integrated into the electronic device as an independent pendant, or may exist as an independent terminal device.

[0108] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0109] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application, such as Figure 6 As shown, the electronic device 3 of this embodiment may include: at least one processor 30 ( Figure 6 Only one processor 30 is shown in the figure), a memory 31, and a computer program 32 stored in the memory 31 and executable on at least one processor 30. When the processor 30 executes the computer program 32, the steps in any of the above-mentioned method embodiments are implemented; or, when the processor 30 executes the computer program 32, the functions of the modules / units in the above-mentioned system embodiments are implemented.

[0110] Exemplarily, the computer program 32 may be divided into one or more modules / units, one or more modules / units are stored in the memory 31, and are executed by the processor 30 to complete the present application. One or more modules / units may be a series of computer program 32 instruction segments capable of completing specific functions, and the instruction segments are used to describe the execution process of the computer program 32 in the electronic device 3.

[0111] The embodiment of the present application further provides a computer-readable storage medium, which stores a computer program 32. When the computer program 32 is executed by the processor 30, the steps in the above-mentioned method embodiments can be implemented.

[0112] An embodiment of the present application provides a computer program product. When the computer program product runs on an electronic device, the electronic device can implement the steps in the above-mentioned method embodiments when executing the computer program product.

[0113] If the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. According to this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, which can be completed by instructing the relevant hardware through a computer program 32, and the computer program 32 can be stored in a computer-readable storage medium, and the computer program 32 can implement the steps of the above-mentioned various method embodiments when executed by the processor 30. Among them, the computer program 32 includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may at least include: any entity or device capable of carrying the computer program code to the terminal, a recording medium, a computer memory, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), an electric carrier signal, a telecommunication signal, and a software distribution medium. For example, a USB flash drive, a mobile hard disk, a magnetic disk or an optical disk. In some jurisdictions, according to legislation and patent practice, computer-readable media cannot be electric carrier signals and telecommunication signals.

[0114] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0115] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0116] In the embodiments provided in the present application, it should be understood that the disclosed devices / network equipment and methods can be implemented in other ways. For example, the device / network equipment embodiments described above are merely schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0117] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0118] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A gradient coil structure of a magnetic resonance device, characterized in that: include: A gradient coil body and at least one sensor group, each sensor group is arranged at a preset position on the gradient coil body, each sensor group includes: a strain sensor and a temperature sensor, the strain sensor in each sensor group is used to detect strain reference information of the corresponding preset position, and the temperature sensor in each sensor group is used to detect temperature reference information of the corresponding preset position.

2. The gradient coil structure of the magnetic resonance apparatus according to claim 1, characterized in that: The strain sensor includes: a fiber Bragg grating strain sensor; the temperature sensor includes: a fiber Bragg grating temperature sensor; The fiber Bragg grating strain sensor is connected to the fiber Bragg grating regulator via a first optical fiber, and the fiber Bragg grating temperature sensor is connected to the fiber Bragg grating regulator via a second optical fiber; or, The fiber Bragg grating strain sensor and the fiber Bragg grating temperature sensor are connected to the fiber Bragg grating regulator through a third optical fiber.

3. The gradient coil structure of the magnetic resonance apparatus according to claim 1, characterized in that: The preset position includes: a preset position in the circumferential direction of the gradient coil body and / or a preset position in the axial direction of the gradient coil body.

4. The gradient coil structure of the magnetic resonance apparatus according to claim 2, characterized in that: The gradient coil structure of the magnetic resonance device also includes: a non-metallic packaging device, through which the fiber Bragg grating temperature sensor is packaged in the gradient coil body, the non-metallic packaging device has a cavity and a small hole connected to the cavity, the optical fiber of the fiber Bragg grating temperature sensor passes through the small hole, one end of the grating area of ​​the fiber Bragg grating temperature sensor is fixed in the small hole, and the other end of the grating area of ​​the fiber Bragg grating temperature sensor is arranged in the cavity.

5. A strain detection method, characterized in that: A gradient coil structure for a magnetic resonance device according to any one of claims 1 to 4, comprising: Acquire temperature reference information of a preset position collected by a temperature sensor in the sensor group, and acquire strain reference information of the preset position collected by a strain sensor in the sensor group; The strain reference information is corrected based on the temperature reference information to determine target strain reference information of the preset position corresponding to the sensor group under the influence of strain.

6. The method according to claim 5, characterized in that The temperature reference information includes: a first central wavelength offset; the strain reference information includes: a second central wavelength offset; The step of correcting the strain reference information based on the temperature reference information to determine the target strain reference information of the preset position under the influence of the strain includes: The target strain reference information of the preset position under the influence of strain is determined by subtracting the first central wavelength offset from the second central wavelength offset.

7. A strain detection device, characterized in that: include: An acquisition module, used to acquire temperature reference information of a preset position collected by a temperature sensor in the sensor group, and strain reference information of the preset position collected by a strain sensor in the sensor group; The correction module is used to correct the strain reference information based on the temperature reference information to determine the target strain reference information of the preset position corresponding to the sensor group under the influence of strain.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 5 to 6 is implemented.

9. A detection system, characterized in that: include: The gradient coil structure of a magnetic resonance device according to any one of claims 1 to 4, the fiber Bragg grating regulator and the electronic device according to claim 8, wherein the fiber Bragg grating regulator is connected to the strain sensor and the temperature sensor in the gradient coil structure of the magnetic resonance device via optical fibers, and the electronic device is connected to the fiber Bragg grating regulator.

10. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the method according to any one of claims 5 to 6 is implemented.

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