Method and device for analyzing stress of metal implant in magnetic resonance environment

Abstract

The invention provides a stress analysis method and device for a metal implant in a magnetic resonance environment. The method comprises the following steps: acquiring an implant model of a to-be-tested metal implant; constructing an external magnetic field space based on the implant model; according to the material used by each component in the to-be-tested metal implant, setting the material attribute of each component in the implant model, and establishing the constitutive relationship of each metal component in the implant model; constructing an external magnetic field environment on the basis of the external magnetic field space; calculating a magnetic induction intensity distribution result in the external magnetic field space; based on the magnetic induction intensity distribution result, the stress result of the implant model in the external magnetic field space is calculated, and the stress result comprises magnetostrictive displacement force and magnetostrictive torque. According to the scheme, the product design risk of the metal implant can be greatly reduced, and the product development efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of human implant technology, and more specifically to a method and apparatus for force analysis of metal implants in a magnetic resonance environment. Background Technology

[0002] Magnetic resonance imaging (MRI) is a medical imaging technique based on the principle of nuclear magnetic resonance. It constructs high-resolution tomographic images by detecting the magnetic resonance signals of hydrogen nuclei within the human body, offering advantages such as being radiation-free, non-invasive, and providing high soft tissue contrast. It plays a crucial role in diagnosing neurological diseases, musculoskeletal disorders, cardiovascular diseases, and many other types of illnesses. With the continuous development of medical technology, MRI, as an important medical imaging diagnostic tool, is increasingly widely used in clinical practice. However, individuals with ferromagnetic metal implants, such as pacemakers, defibrillators, cochlear implants, aneurysm clips, and metal fragments, are often prohibited from undergoing MRI examinations. To address this situation, many implantable devices are conducting MRI compatibility studies to better meet the medical needs of their users.

[0003] For metal implants, the stress they experience under magnetic resonance (MRI) conditions is a key area of ​​research. In current product development processes, it's typically necessary to wait until a prototype is developed before renting MRI equipment to test and verify the magnetostrictive force and torque under MRI conditions. This approach increases product design and manufacturing costs and impacts product development efficiency.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The present invention is proposed in view of the above-mentioned problems. According to one aspect of the present invention, a method for stress analysis of a metal implant in a magnetic resonance environment is provided, comprising: Obtain an implant model of the metal implant to be tested; Based on the implant model, an external magnetic field space is constructed; Based on the materials used in each component of the metal implant under test, the material properties of each component in the implant model are set, and the constitutive relationship of each metal component in the implant model is established. An external magnetic field environment is constructed based on the aforementioned external magnetic field space; Calculate the magnetic induction intensity distribution within the external magnetic field space; Based on the magnetic induction intensity distribution, the force results of the implant model in the external magnetic field space are calculated, including magneto-induced displacement force and magneto-induced torque.

[0006] For example, the calculation of the magnetic flux density distribution within the external magnetic field space includes: According to a preset size, the external magnetic field space and the implant model are divided into multiple polyhedral meshes; Based on Maxwell's theory and the principle of magnetization dynamics, the control equations consisting of the control equations corresponding to the multiple polyhedral meshes are solved to obtain the magnetic induction intensity distribution results. Preferably, the preset size is 1 / 5 of the minimum geometric size of the implant model; Preferably, the method further includes: adjusting the preset size based on grid adjustment information input by the user.

[0007] For example, constructing an external magnetic field space based on the implant model includes: Obtain the geometric center and longest dimension of the implant model; The geometric center of the implant is defined as the origin of the spatial coordinates of the external magnetic field space, wherein the external magnetic field space is a cube; The preset multiple of the longest dimension is determined as the side length of the external magnetic field space, and the preset multiple is a preset value or a value determined based on user input information; The coordinates of each vertex of the external magnetic field space are determined based on the side length and the origin of the spatial coordinates, and the external magnetic field space is constructed based on the vertex coordinates.

[0008] Exemplarily, before constructing the external magnetic field space based on the implant model, the method further includes: The non-metallic and paramagnetic metallic portions in the implant model are simplified.

[0009] For example, the metal implant is a cochlear implant, and the simplified implant model includes electronic components and an implanted magnet.

[0010] For example, after obtaining the force result, the method further includes: Compare the magnetoinduced displacement force with the displacement force threshold; Compare the magnetostrictive torque with the torque threshold; When the force result meets the safety conditions, the metal implant under test is determined to be compliant, wherein the safety conditions are: the magnetostrictive displacement force is less than or equal to the displacement force threshold, and the magnetostrictive torque is less than or equal to the torque threshold; Preferably, the method further includes: when the force result does not meet the safety conditions, outputting a prompt message to remind the user to optimize the metal implant under test.

[0011] Exemplarily, the method further includes: The implant model, the external magnetic field space, and the force results are displayed.

[0012] The present invention also provides a force analysis device for metal implants in a magnetic resonance environment, comprising: The model generation module is used to obtain the implant model of the metal implant to be tested, and to construct an external magnetic field space based on the implant model; The material parameter module is used to set the material properties of each component in the implant model according to the materials used in each component of the metal implant under test, and to establish the constitutive relationship of each metal component in the implant model. A magnetic field generating module is used to construct an external magnetic field environment based on the external magnetic field space. The calculation and analysis module is used to calculate the magnetic induction intensity distribution in the external magnetic field space, and, based on the magnetic induction intensity distribution, to calculate the force results of the implant model in the external magnetic field space, the force results including magnetostrictive displacement force and magnetostrictive torque.

[0013] According to another aspect of the present invention, an electronic device is provided, including a processor and a memory, wherein the memory stores a computer program, and the processor is used to execute the computer program to implement the method as described above.

[0014] According to another aspect of the present invention, a computer-readable storage medium is provided, which stores a computer program / instructions that, when executed by a processor, implement the method described above.

[0015] The above technical solution detects the stress of the metal implant under test in a magnetic resonance environment in a simulation environment. It does not require waiting for the sample to be developed. It can verify the stress of the metal implant in magnetic resonance environments with different field strengths and various working conditions during the product design stage, thereby guiding product design and optimization, greatly reducing product design risks and improving product development efficiency.

[0016] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0017] The above and other objects, features, and advantages of the present invention will become more apparent from the more detailed description of the embodiments of the invention in conjunction with the accompanying drawings. The drawings are provided to further illustrate the embodiments of the invention and form part of the specification. They are used together with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings, the same reference numerals generally represent the same parts or steps.

[0018] Figure 1 A schematic flowchart illustrating a method for stress analysis of a metal implant in a magnetic resonance environment according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of an external magnetic field space according to an embodiment of the present invention is shown; Figure 3 Show Figure 2 A schematic diagram of the structure of the implant model; Figure 4 A schematic diagram of a force analysis device according to an embodiment of the present invention is shown; Figure 5 A schematic block diagram of an electronic device according to an embodiment of the present invention is shown.

[0019] Figure 2 In the middle: 201, implant model; 202, external magnetic field space. Figure 3 In China: 2011, implanted magnet; 2012, receiving coil wire; 2013, stimulator housing; 2014, electronic device; 2015, electrode wire; 2016, stimulating electrode. Detailed Implementation

[0020] To make the objectives, technical solutions, and advantages of the present invention more apparent, exemplary embodiments according to the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are merely a part of the embodiments of the present invention, and not all of the embodiments of the present invention. It should be understood that the present invention is not limited to the exemplary embodiments described herein. Based on the embodiments of the present invention described herein, all other embodiments obtained by those skilled in the art without inventive effort should fall within the protection scope of the present invention.

[0021] According to one aspect of the present invention, a method for stress analysis of metal implants in a magnetic resonance environment is provided. Figure 1 A schematic flowchart illustrating a method for stress analysis of a metallic implant in a magnetic resonance environment according to an embodiment of the present invention is shown. Figure 1 As shown, the method may include steps S110, S120, S130, S140, S150 and S160.

[0022] In step S110, an implant model of the metal implant to be tested is obtained.

[0023] The metal implant models to be tested in this article include, but are not limited to, cochlear implants, cardiac stents, and artificial joints.

[0024] In this example, detailed modeling of each component of the implant can be performed in advance as needed to obtain the geometric model of the implant (i.e., the implant model). This modeling method includes, but is not limited to, modeling using 3D software such as CREO, UG, SolidWorks, CATIA, Rhino, ZW3D, and GstarCAD 3D, or inputting the dimensions of each part of the metal implant to be tested into a pre-built parametric model to obtain the geometric model, which will not be elaborated further.

[0025] In step S120, an external magnetic field space is constructed based on the implant model.

[0026] After obtaining the implant model, an external magnetic field space can be constructed to enclose it, facilitating the simulation of the MRI environment. The shape of this external magnetic field space can be chosen as needed, for example, it can be a cube, cuboid, sphere, ellipsoid, or other polyhedrons; this paper does not impose any restrictions on this. The size of the external magnetic field space can be a preset size, in which case the implant model can be directly moved to the center of the external magnetic field space. Of course, the size of the external magnetic field space can also be adaptively adjusted according to the size of the implant model, for example, it can be 10 to 1,000,000 times the volume of the implant model.

[0027] Figure 2 A schematic diagram of an external magnetic field space according to an embodiment of the present invention is shown. Figure 2 In the middle, the implant model 201 is located at the center of the external magnetic field space 202.

[0028] In step S130, based on the materials used in each component of the metal implant to be tested, the material properties of each component in the implant model are set, and the constitutive relationship of each metal component in the implant model is established.

[0029] It is understood that the metal implant under test is typically composed of multiple components. In the scheme of this example, the material properties and constitutive relations of each component can be set separately according to the different materials of each component. Material properties include, but are not limited to, relative permeability, Young's modulus, Poisson's ratio, stress-strain curve, density, etc. At the same time, constitutive relations can be established for each metal component according to the material type, that is, appropriate magnetization models can be established for the components of the implant using metal materials according to the metal type and characteristics, including but not limited to relative permeability, magnetic loss, BH curve, magnetization, remanent magnetic flux density, hysteresis model, etc. Those skilled in the art will understand the process of establishing constitutive relations, which will not be elaborated here. The cochlear implant is used as an example for illustration. Figure 3 Show Figure 2 A schematic diagram of the implant model. (See attached diagram.) Figure 3 As shown, the implant model 201 includes an implanted magnet 2011, a receiving coil wire 2012, a stimulator housing 2013, electronic devices 2014 (mainly including a decoding stimulator), electrode wires 2015, and stimulating electrodes 2016. The materials of the different components vary. Specifically, the receiving coil wire 2012, stimulator housing 2013, electrode wires 2015, and stimulating electrodes 2016 are composed of paramagnetic materials, the electronic device 2014 typically contains ferromagnetic materials, and the implanted magnet 2011 is typically a samarium cobalt permanent magnet or a neodymium iron boron permanent magnet. For the electronic device 2014, the relative permeability or BH curve can be assigned according to the type of ferromagnetic material. The relative permeability of iron is approximately 1.0065~1.0085, and the relative permeability of nickel is approximately 1.0069~1.0075, specifically determined by the material grade, or the material's BH curve can be obtained experimentally. For the implanted magnet 2011, the magnetization constitutive relation, remanent flux density constitutive relation, or hysteresis model constitutive relation can be selected according to the specific material type of the magnetic core. The corresponding parameters, such as recovery permeability, remanent flux density modulus, remanent flux direction, saturation magnetization, and initial magnetization, can be input according to the selected constitutive relation. The relative permeability of samarium cobalt permanent magnets is about 1.02~1.07, and the relative permeability of neodymium iron boron permanent magnets is about 1.05~1.1.

[0030] In step S140, an external magnetic field environment is constructed based on the external magnetic field space.

[0031] In this example, a simulated magnetic resonance imaging (MRI) scan can be achieved using a constructed external magnetic field environment. Specifically, the static magnetic field strength, gradient field strength, magnetic field direction, and boundary conditions of the external magnetic field space can be set according to simulation requirements. The magnetic field excitation source can be a static magnetic field, a gradient magnetic field, or a combination thereof. There are no restrictions on the magnetic field strength value; it can be 0.1T, 0.2T, 0.5T, 1.0T, 1.5T, 3.0T, 5.0T, 7.0T, 10.0T, or higher static magnetic field values. Boundary conditions of the external magnetic field space include, but are not limited to, magnetic flux conservation and magnetic insulation.

[0032] In step S150, the magnetic induction intensity distribution in the external magnetic field space is calculated.

[0033] After constructing the external magnetic field environment, the magnetic induction distribution in the magnetic field space can be calculated. Specifically, this can be done using the finite element method (FEM), boundary element method (BEM), Maxwell's theory, and the principles of magnetization dynamics, etc., which will not be elaborated upon here.

[0034] In step S160, based on the magnetic induction intensity distribution results, the force results of the implant model in the external magnetic field space are calculated, including magneto-induced displacement force and magneto-induced torque.

[0035] After obtaining the magnetic flux density distribution within the magnetic field space, the force on the implant model in the external magnetic field space can be calculated based on this result. For example, the force on the implant in a magnetic resonance environment can be calculated using Maxwell's stress tensor integral method, which will not be elaborated further.

[0036] The above technical solution detects the stress of the metal implant under test in a magnetic resonance environment in a simulation environment. It does not require waiting for the sample to be developed. It can verify the stress of the metal implant in magnetic resonance environments with different field strengths and various working conditions during the product design stage, thereby guiding product design and optimization, greatly reducing product design risks and improving product development efficiency.

[0037] For example, calculating the magnetic induction intensity distribution in the external magnetic field space includes: dividing the external magnetic field space and the implant model into multiple polyhedral meshes according to a preset size; and solving the set of control equations composed of the control equations corresponding to the multiple polyhedral meshes based on Maxwell's theory and the principle of magnetization dynamics to obtain the magnetic induction intensity distribution.

[0038] The polyhedral mesh can be hexahedral or tetrahedral. In this example, the physical model is discretized into smaller units by meshing, which improves computational accuracy. It's understood that a denser mesh and more units result in higher computational accuracy, but also increase computational complexity. The size of the polyhedral mesh in this example can be a preset size or modified according to user needs. In some embodiments, the preset size is 1 / 5 of the minimum geometric feature size of the implant model. In other embodiments, the method further includes adjusting the preset size based on user-inputted mesh adjustment information. In this embodiment, the user can manually adjust the mesh size settings according to the mesh generation effect, thereby balancing computational accuracy and efficiency.

[0039] It can be understood that a polyhedral mesh is a discrete element, and each discrete element corresponds to a set of governing equations. The governing equations of the entire physical model are composed of the governing equations of all discrete elements. Therefore, by solving the set of governing equations of the physical model, the magnetic flux density distribution throughout the entire magnetic field space can be obtained. The size of the set of governing equations is directly related to the number of meshes. Those skilled in the art will understand the specific implementation methods for solving the above-mentioned set of governing equations based on Maxwell's theory and the principles of magnetization dynamics, which will not be elaborated here.

[0040] The aforementioned technical solution achieves precise adaptation to complex geometric structures by dividing the external magnetic field space and the implant model into polyhedral meshes of a predetermined size. Then, based on Maxwell's theory and the principles of magnetization dynamics, the governing equations corresponding to each mesh are solved to ultimately obtain the magnetic flux density distribution. This approach ensures the accuracy of the calculations by relying on core physical laws while balancing computational precision and efficiency through mesh discretization. It provides reliable data support for subsequent calculations of key safety parameters such as magnetostrictive force and torque of metal implants.

[0041] For example, constructing an external magnetic field space based on an implant model includes: obtaining the geometric center and longest dimension of the implant model; determining the geometric center of the implant as the origin of the spatial coordinates of the external magnetic field space, wherein the external magnetic field space is a cube; determining a preset multiple of the longest dimension as the side length of the external magnetic field space, wherein the preset multiple is a preset value or a value determined based on user input information; determining the coordinates of each vertex of the external magnetic field space according to the side length and the origin of the spatial coordinates, and constructing the external magnetic field space based on the vertex coordinates.

[0042] For example, after obtaining the implant model, its geometric center and longest dimension L can be detected. The geometric center of the implant is automatically placed at spatial coordinates (0, 0, 0). The automatically generated external magnetic field space is a cube by default, and its geometric center is also located at spatial coordinates (0, 0, 0). The side length of the external magnetic field space is several times the longest dimension L of the implant, denoted as 2nL. The coordinates of the eight vertices are (nL, nL, nL), (nL, -nL, nL), (-nL, nL, nL), (-nL, -nL, nL), (nL, nL, -nL), (nL, -nL, -nL), (-nL, -nL, -nL), (-nL, -nL, -nL). The value of n can be manually set, n≥0.5.

[0043] The above technical solution constructs an external magnetic field space based on the geometric features of the implant itself. By setting the geometric center of the implant as the origin of the cube space and setting the side length as a preset multiple of the longest dimension, it can ensure that the magnetic field space accurately covers the implant and the surrounding key areas, avoiding waste of computational resources or omission of the magnetic field influence range. It can also quickly determine the coordinates of the spatial vertices based on the inherent parameters of the implant, realizing the efficient and standardized construction of the magnetic field space. At the same time, the side length can be flexibly adjusted according to the implant type and simulation requirements, taking into account both universality and personalization, laying a reasonable and accurate spatial foundation for subsequent magnetic field distribution calculations.

[0044] For example, before constructing the external magnetic field space based on the implant model, the method further includes: simplifying the non-metallic and paramagnetic metallic portions in the implant model.

[0045] It is understandable that the displacement forces and torques contributed by non-metallic and paramagnetic metallic materials in a magnetic resonance environment are negligible. In this approach, by simplifying the non-metallic and paramagnetic metallic parts of the implant model before constructing the external magnetic field space, the subsequent magnetic field calculation process can be significantly optimized while ensuring simulation accuracy. Specifically, since the magneto-induced displacement forces and torques generated by non-metallic and paramagnetic metallic materials in a magnetic resonance environment are negligible, simplification will not affect the calculation results of core safety parameters. At the same time, simplification can significantly reduce the geometric complexity and mesh number of the model, reduce the computational power consumption of subsequent magnetic field space construction and magnetic induction intensity distribution calculation, shorten the simulation cycle, and balance the accuracy and efficiency of the simulation, providing a more efficient pre-processing solution for MRI safety testing of metallic implants.

[0046] Simplification of non-metallic and paramagnetic metallic parts can be achieved, but is not limited to, removing relevant components or structurally fusing them with adjacent non-metallic materials. Taking a cochlear implant as an example, since the receiving coil wire 2012, stimulator shell 2013, electrode wire 2015, and stimulating electrode 2016 of the cochlear implant are all composed of paramagnetic materials, these structural components can be removed or structurally fused with adjacent non-metallic materials. In this case, the simplified implant model includes electronic devices and implanted magnets.

[0047] For example, after obtaining the force result, the method further includes: comparing the magnetostrictive displacement force with the displacement force threshold; comparing the magnetostrictive torque with the torque threshold; and determining that the metal implant under test is compliant when the force result meets the safety conditions, wherein the safety conditions are: the magnetostrictive displacement force is less than or equal to the displacement force threshold, and the magnetostrictive torque is less than or equal to the torque threshold.

[0048] The displacement force threshold and torque threshold can be determined according to regulations or relevant provisions. Taking cochlear implants as an example, according to the requirements of ISO 14708-7 for magnetostrictive torque and magnetostrictive displacement force in a magnetic resonance environment, the magnetostrictive torque should not be greater than the gravitational torque of the implant or a larger value with scientific evidence, and the magnetostrictive displacement force should not be greater than the self-weight of the implant or a larger value with scientific evidence.

[0049] After obtaining the stress results, the above technical solution further evaluates the compliance of the metal implant under test based on the stress results. The compliance determination of the metal implant under test can be completed without human intervention, which helps to further improve product development efficiency.

[0050] For example, the method further includes: outputting a prompt message when the force result does not meet safety conditions, to remind the user to optimize the metal implant under test. When the simulation results show that the currently designed metal implant under test does not meet regulatory requirements, prompt messages can be output through text, images, audio, etc., so that the user can promptly identify the non-compliance of the metal implant under test and optimize it in a timely manner. Taking the implant as a cochlear implant as an example, the optimization method may include, but is not limited to, reducing the size of the magnet inside the implant, changing the magnet material, reducing the proportion of ferromagnetic materials used, etc. The specific method can be selected according to the actual research and development, and will not be elaborated here.

[0051] Exemplarily, the method further includes displaying the implant model, the external magnetic field space, and the force results. Additionally, information such as mesh generation results, magnetic field excitation direction, and magnetic induction intensity distribution can be displayed for user viewing. In the above embodiments for determining whether the tested metal implant is compliant, the compliance status (i.e., whether it is compliant) of the tested metal implant can also be displayed. When the tested metal implant is non-compliant, the user can directly select an optimization scheme based on the size, material, and other information of the implant model displayed on the screen. This helps improve user experience and increase R&D efficiency.

[0052] According to another aspect of the present invention, a stress analysis device for metal implants in a magnetic resonance environment is provided. Figure 4 A schematic diagram of a force analysis device according to an embodiment of the present invention is shown. Figure 4 As shown, the device may include a model generation module 410, a material parameter module 420, a magnetic field generation module 430, and a calculation and analysis module 440.

[0053] The model generation module 410 is used to obtain the implant model of the metal implant to be tested, and to construct an external magnetic field space based on the implant model.

[0054] The material parameter module 420 is used to set the material properties of each component in the implant model according to the materials used in each component of the metal implant under test, and to establish the constitutive relationship of each metal component in the implant model.

[0055] The magnetic field generating module 430 is used to construct an external magnetic field environment based on the external magnetic field space.

[0056] The calculation and analysis module 440 is used to calculate the magnetic induction intensity distribution in the external magnetic field space, and, based on the magnetic induction intensity distribution, to calculate the force results of the implant model in the external magnetic field space, including magneto-induced displacement force and magneto-induced torque.

[0057] In some embodiments, the device may further include a display module, which can be used to display the geometric model of the implant, the spatial morphology of the external magnetic field, the mesh division results, the magnetic field excitation direction, the magnetic induction intensity distribution, and the force results of the implant.

[0058] According to another aspect of the present invention, an electronic device is also provided. Figure 5 A schematic block diagram of an electronic device according to an embodiment of the present invention is shown. Figure 5 As shown, the electronic device 500 includes a processor 510 and a memory 520. The memory 520 stores a computer program, which the processor 510 executes to implement the method described above.

[0059] According to another aspect of the present invention, a computer-readable storage medium is also provided. The storage medium stores a computer program / instructions that, when executed by a processor, implement the method described above. The storage medium may, for example, include a read-only memory (ROM), an erasable programmable read-only memory (EPROM), a portable compact disc read-only memory (CD-ROM), a USB memory, or any combination of the above storage media. The computer-readable storage medium may be any combination of one or more computer-readable storage media.

[0060] Those skilled in the art will readily understand the implementation structure, working principle, and beneficial effects of the corresponding devices, electronic devices, and computer-readable storage media by reading the above methods. For the sake of brevity, further details will not be elaborated here.

[0061] Although exemplary embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above exemplary embodiments are merely illustrative and are not intended to limit the scope of the invention. Various changes and modifications can be made therein by those skilled in the art without departing from the scope and spirit of the invention. All such changes and modifications are intended to be included within the scope of the invention as claimed in the appended claims.

[0062] Those skilled in the art will recognize that the units and algorithm steps of the various examples 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 implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementations should not be considered beyond the scope of this invention.

[0063] In the several embodiments provided by this invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another device, or some features may be ignored or not executed.

[0064] Numerous specific details are set forth in the specification provided herein. However, it will be understood that embodiments of the invention may be practiced without these specific details. In some instances, well-known methods, structures, and techniques have not been shown in detail so as not to obscure the understanding of this specification.

[0065] Similarly, it should be understood that, in order to streamline the invention and aid in understanding one or more of the various aspects of the invention, features of the invention are sometimes grouped together in a single embodiment, figure, or description thereof in the description of exemplary embodiments of the invention. However, this approach should not be construed as reflecting an intention that the claimed invention requires more features than are expressly recited in each claim. Rather, as reflected in the corresponding claims, its inventive point lies in solving the corresponding technical problem with fewer features than all of those in a single disclosed embodiment. Therefore, the claims following the detailed description are hereby expressly incorporated into that detailed description, wherein each claim itself is a separate embodiment of the invention.

[0066] Those skilled in the art will understand that, apart from the mutual exclusion of features, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or elements of any method or apparatus so disclosed may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose.

[0067] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features but not others included in other embodiments, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0068] The various component embodiments of the present invention can be implemented in hardware, or as software modules running on one or more processors, or a combination thereof. Those skilled in the art will understand that microprocessors or digital signal processors (DSPs) can be used in practice to implement some or all of the functions of some modules in the apparatus or electronic device according to embodiments of the present invention. The present invention can also be implemented as an apparatus program (e.g., a computer program and computer program product) for performing some or all of the methods described herein. Such programs implementing the present invention can be stored on a computer-readable medium or can be in the form of one or more signals. Such signals can be downloaded from an Internet website, provided on a carrier signal, or provided in any other form.

[0069] It should be noted that the above embodiments are illustrative of the invention and not restrictive, and that those skilled in the art can devise alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses should not be construed as limiting the claims. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims enumerating several means, several of these means may be embodied by the same item of hardware. The use of the words first, second, and third, etc., does not indicate any order. These words can be interpreted as names.

[0070] The above description is merely a specific embodiment of the present invention or an explanation of that embodiment. The scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for force analysis of metal implants in a magnetic resonance environment, characterized in that, include: Obtain an implant model of the metal implant to be tested; Based on the implant model, an external magnetic field space is constructed; Based on the materials used in each component of the metal implant under test, the material properties of each component in the implant model are set, and the constitutive relationship of each metal component in the implant model is established. An external magnetic field environment is constructed based on the aforementioned external magnetic field space; Calculate the magnetic induction intensity distribution within the external magnetic field space; Based on the magnetic induction intensity distribution, the force results of the implant model in the external magnetic field space are calculated, including magneto-induced displacement force and magneto-induced torque.

2. The method according to claim 1, characterized in that, The calculation of the magnetic flux density distribution within the external magnetic field space includes: According to a preset size, the external magnetic field space and the implant model are divided into multiple polyhedral meshes; Based on Maxwell's theory and the principle of magnetization dynamics, the control equations consisting of the control equations corresponding to the multiple polyhedral meshes are solved to obtain the magnetic induction intensity distribution results. Preferably, the preset size is 1 / 5 of the minimum geometric size of the implant model; Preferably, the method further includes: adjusting the preset size based on grid adjustment information input by the user.

3. The method according to claim 1, characterized in that, The construction of an external magnetic field space based on the implant model includes: Obtain the geometric center and longest dimension of the implant model; The geometric center of the implant is defined as the origin of the spatial coordinates of the external magnetic field space, wherein the external magnetic field space is a cube; The preset multiple of the longest dimension is determined as the side length of the external magnetic field space, and the preset multiple is a preset value or a value determined based on user input information; The coordinates of each vertex of the external magnetic field space are determined based on the side length and the origin of the spatial coordinates, and the external magnetic field space is constructed based on the vertex coordinates.

4. The method according to claim 1, characterized in that, Before constructing the external magnetic field space based on the implant model, the method further includes: The non-metallic and paramagnetic metallic portions in the implant model are simplified.

5. The method according to claim 4, characterized in that, The metal implant is a cochlear implant, and the simplified implant model includes electronic components and an implanted magnet.

6. The method according to claim 1, characterized in that, After obtaining the force result, the method further includes: Compare the magnetoinduced displacement force with the displacement force threshold; Compare the magnetostrictive torque with the torque threshold; When the force result meets the safety conditions, the metal implant under test is determined to be compliant, wherein the safety conditions are: the magnetostrictive displacement force is less than or equal to the displacement force threshold, and the magnetostrictive torque is less than or equal to the torque threshold; Preferably, the method further includes: when the force result does not meet the safety conditions, outputting a prompt message to remind the user to optimize the metal implant under test.

7. The method according to any one of claims 1-6, characterized in that, The method further includes: The implant model, the external magnetic field space, and the force results are displayed.

8. A force analysis device for a metal implant in a magnetic resonance environment, characterized in that, include: The model generation module is used to obtain the implant model of the metal implant to be tested, and to construct an external magnetic field space based on the implant model; The material parameter module is used to set the material properties of each component in the implant model according to the materials used in each component of the metal implant under test, and to establish the constitutive relationship of each metal component in the implant model. A magnetic field generating module is used to construct an external magnetic field environment based on the external magnetic field space. The calculation and analysis module is used to calculate the magnetic induction intensity distribution in the external magnetic field space, and, based on the magnetic induction intensity distribution, to calculate the force results of the implant model in the external magnetic field space, the force results including magnetostrictive displacement force and magnetostrictive torque.

9. An electronic device, characterized in that, It includes a processor and a memory, wherein the memory stores a computer program, and the processor is used to execute the computer program to implement the method as claimed in any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, The system stores a computer program / instructions that, when executed by a processor, implement the method as described in any one of claims 1-7.

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