阅读说明：本技术 8字形经颅磁刺激线圈、磁刺激装置及磁刺激系统 (8-shaped transcranial magnetic stimulation coil, magnetic stimulation device and magnetic stimulation system ) 是由 刘仲武 吴雅祥 余红雅 李静 于 2021-08-30 设计创作，主要内容包括：本发明公开了一种8字形经颅磁刺激线圈、磁刺激装置及磁刺激系统,其中经颅磁刺激线圈包括：8字形线圈,包括两个通孔；软磁磁芯,安装在所述8字形线圈的中心位置,所述软磁磁芯呈U型,包括两个柱体以及连接所述两个柱体的横梁,两个所述柱体分别置入所述两个通孔内；在所述通孔的横截面上,所述柱体的中心处于所述通孔的中心与所述通孔的边之间。本发明通过在8字形线圈上安装小尺寸的软磁磁芯,且该软磁磁芯与8字形线圈之间采用偏心结构,提升8字形线圈沿磁芯方向刺激的精度。本发明可广泛应用于医疗设备技术领域。(The invention discloses an 8-shaped transcranial magnetic stimulation coil, a magnetic stimulation device and a magnetic stimulation system, wherein the transcranial magnetic stimulation coil comprises: the 8-shaped coil comprises two through holes; the soft magnetic core is arranged in the center of the 8-shaped coil, is U-shaped and comprises two columns and a cross beam connected with the two columns, and the two columns are respectively arranged in the two through holes; on the cross section of the through hole, the center of the column body is positioned between the center of the through hole and the edge of the through hole. According to the invention, the small-sized soft magnetic core is arranged on the 8-shaped coil, and an eccentric structure is adopted between the soft magnetic core and the 8-shaped coil, so that the stimulation precision of the 8-shaped coil along the direction of the magnetic core is improved. The invention can be widely applied to the technical field of medical equipment.)

1. A figure-8 transcranial magnetic stimulation coil, comprising:

the 8-shaped coil comprises two through holes;

the soft magnetic core is arranged in the center of the 8-shaped coil, is U-shaped and comprises two columns and a cross beam connected with the two columns, and the two columns are respectively arranged in the two through holes;

on the cross section of the through hole, the center of the column body is positioned between the center of the through hole and the edge of the through hole.

2. The figure-8 transcranial magnetic stimulation coil according to claim 1, wherein the soft magnetic core is made of a material with high magnetic permeability and high saturation magnetization.

3. The figure-8 transcranial magnetic stimulation coil according to claim 1, wherein in a cross section of the through hole, an area of the column is far smaller than an area of the through hole.

4. The 8-shaped transcranial magnetic stimulation coil according to claim 1, wherein the planes in which the two through holes are located form an included angle.

5. The 8-shaped transcranial magnetic stimulation coil according to claim 1, wherein the cylinder is a cylinder, a polygonal prism or a polygonal pyramid.

6. The 8-shaped transcranial magnetic stimulation coil according to claim 1, wherein the through hole is circular, oval or polygonal in shape.

7. The 8-shaped transcranial magnetic stimulation coil according to claim 1, wherein the soft magnetic core is a homogeneous U-shaped magnetic core, a magnetic core formed by stacking a plurality of layers of iron-based soft magnetic sheets or a magnetic core formed by stacking a plurality of layers of amorphous strips.

8. The 8-shaped transcranial magnetic stimulation coil according to claim 1, wherein the magnetic induction intensity of the soft magnetic core after being magnetized is expressed as follows:

B＝μ₀μ_rH

wherein, mu₀Is a vacuum permeability, mu_rH is the magnetic field strength in the figure-8 coil in which the soft magnetic core is located, which is the relative permeability of the magnetic material.

9. A transcranial magnetic stimulation device, comprising:

transcranial magnetic stimulation coil implemented using a figure-8 transcranial magnetic stimulation coil according to any one of claims 1-8; and the power supply is used for providing alternating current with preset frequency for the transcranial magnetic stimulation coil.

10. A transcranial magnetic stimulation system, comprising a box and a plurality of transcranial magnetic stimulation devices according to claim 9, wherein the transcranial magnetic stimulation devices are placed in the box.

Technical Field

The invention relates to the technical field of medical equipment, in particular to an 8-shaped transcranial magnetic stimulation coil, a magnetic stimulation device and a magnetic stimulation system.

Background

Transcranial Magnetic Stimulation (TMS) is a powerful tool used in the neuroscience field to study brain function. Clinical results also indicate that TMS has therapeutic effects on neurological diseases, psychiatric diseases, neuropathic pain and depression. The working principle of TMS can be explained by electromagnetic induction phenomenon, and an external magnetic stimulation coil is used for generating an electric field which is enough to depolarize neurons at the position needing stimulation in the intracranial space, so that the change of a nerve cell layer and a behavior layer is caused. TMS can still affect a period of time after stimulation is applied and therefore has significant medical value.

The 8-shaped coil is a TMS coil which is commonly used at present and used for accurately stimulating a specific intracranial region, compared with TMS coils with other shapes, the 8-shaped coil has relatively concentrated stimulation regions generated in the cranium, but due to the working principle of TMS, the range of the electric field intensity generated by the coil, which exceeds the nerve stimulation threshold value, is still a larger region on the cerebral cortex, and effective and accurate stimulation cannot be realized.

Disclosure of Invention

To solve at least one of the technical problems in the prior art to a certain extent, the present invention provides an 8-shaped transcranial magnetic stimulation coil, a magnetic stimulation device and a magnetic stimulation system.

The technical scheme adopted by the invention is as follows:

a figure-8 transcranial magnetic stimulation coil comprising:

the 8-shaped coil comprises two through holes;

the soft magnetic core is arranged in the center of the 8-shaped coil, is U-shaped and comprises two columns and a cross beam connected with the two columns, and the two columns are respectively arranged in the two through holes;

on the cross section of the through hole, the center of the column body is positioned between the center of the through hole and the edge of the through hole.

Furthermore, the soft magnetic core is made of a material with high magnetic permeability and high saturation magnetization.

Further, in the cross section of the through hole, the area of the column is far smaller than that of the through hole.

Furthermore, an included angle is formed between planes of the two through holes.

Further, the cylinder is a cylinder, a polygonal prism or a polygonal pyramid.

Further, the shape of the through hole is circular, oval or polygonal.

Further, the soft magnetic core is a homogeneous U-shaped magnetic core, a magnetic core formed by stacking a plurality of layers of iron-based soft magnetic sheets or a magnetic core formed by stacking a plurality of layers of amorphous strips.

Further, the expression of the magnetic induction after the soft magnetic core is magnetized is as follows:

B＝μ₀μ_rH

wherein, mu₀Is a vacuum permeability, mu_rH is the magnetic field strength in the figure-8 coil in which the soft magnetic core is located, which is the relative permeability of the magnetic material. Further, the air conditioner is provided with a fan,

the other technical scheme adopted by the invention is as follows:

a transcranial magnetic stimulation device comprising:

the transcranial magnetic stimulation coil is realized by adopting the 8-shaped transcranial magnetic stimulation coil;

and the power supply is used for providing alternating current with preset frequency for the transcranial magnetic stimulation coil.

The other technical scheme adopted by the invention is as follows:

a transcranial magnetic stimulation system comprises a box body and a plurality of transcranial magnetic stimulation devices which are placed in the box body.

The invention has the beneficial effects that: according to the invention, the small-sized soft magnetic core is arranged on the 8-shaped coil, and an eccentric structure is adopted between the soft magnetic core and the 8-shaped coil, so that the stimulation precision of the 8-shaped coil along the direction of the magnetic core is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following description is made on the drawings of the embodiments of the present invention or the related technical solutions in the prior art, and it should be understood that the drawings in the following description are only for convenience and clarity of describing some embodiments in the technical solutions of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is a diagram of a model of the effect of a figure-8 transcranial magnetic stimulation coil on the stimulation effect in an embodiment of the present invention;

FIG. 2 is a bottom view of a soft magnetic core in an embodiment of the present invention;

FIG. 3 is a side view of a soft magnetic core in an embodiment of the present invention;

FIG. 4 is a y-z cross-sectional view of the axis of symmetry of the model shown in FIG. 1;

FIG. 5 is a comparison graph of the induced electric field intensity generated by a coil without a magnetic core and a magnetic core with a concentric 8-shaped coil according to an embodiment of the present invention;

FIG. 6 is a diagram showing an example of the present invention in which a magnetic core concentric with the figure-8 coil is added and a coil without a magnetic core is used_θ/E₀A comparison graph of the ratios;

FIG. 7 shows the theta values of the present invention in the embodiment of the present invention, which correspond to the case where a core concentric with the 8-shaped coil is added, the case where a core eccentric to the 8-shaped coil is added, and the case where no core is added₀Alignment of angles.

FIG. 8 is a graph showing the effect of adding a magnetic core eccentric to the figure-8 coil and a stimulation range of a coil without the magnetic core in an embodiment of the present invention;

fig. 9 is a schematic diagram of an embodiment of the present invention incorporating a magnetic core concentric with the figure-8 coil.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the accompanying drawings are illustrative only for the purpose of explaining the present invention, and are not to be construed as limiting the present invention. The step numbers in the following embodiments are provided only for convenience of illustration, the order between the steps is not limited at all, and the execution order of each step in the embodiments can be adapted according to the understanding of those skilled in the art.

In the description of the present invention, it should be understood that the orientation or positional relationship referred to in the description of the orientation, such as the upper, lower, front, rear, left, right, etc., is based on the orientation or positional relationship shown in the drawings, and is only for convenience of description and simplification of description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention.

In the description of the present invention, the meaning of a plurality of means is one or more, the meaning of a plurality of means is two or more, and larger, smaller, larger, etc. are understood as excluding the number, and larger, smaller, inner, etc. are understood as including the number. If the first and second are described for the purpose of distinguishing technical features, they are not to be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or implicitly indicating the precedence of the technical features indicated.

In the description of the present invention, unless otherwise explicitly limited, terms such as arrangement, installation, connection and the like should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meanings of the above terms in the present invention in combination with the specific contents of the technical solutions.

As shown in fig. 1, 2 and 3, the present embodiment provides an 8-shaped transcranial magnetic stimulation coil, comprising:

the 8-shaped coil 2 comprises two through holes;

the soft magnetic core 1 is arranged at the central position of the 8-shaped coil 2, the soft magnetic core 1 is U-shaped and comprises two columns and a cross beam for connecting the two columns, and the two columns are respectively arranged in the two through holes;

on the cross section of the through hole, the center of the column body is positioned between the center of the through hole and the edge of the through hole.

In the embodiment, the soft magnetic core with small size is arranged at the central position of the 8-shaped coil, the 8-shaped coil and the soft magnetic core are eccentric, and the soft magnetic core is matched with the 8-shaped coil, so that the purpose of improving the stimulation precision of the 8-shaped coil along the direction of the magnetic core is achieved; as shown in fig. 1, the center position of the figure-8 coil refers to a position where two coils in the figure-8 coil are connected. As shown in fig. 1, the eccentricity between the figure-8 coil and the soft magnetic core means: the center of the through hole of the 8-shaped coil is not coincident with the center of the column.

In some alternative embodiments, the cross-section of the coils of the figure-8 coil is not limited to shapes such as rectangular, oval, multi-strand coils, and the like.

In some alternative embodiments, the coil of the figure-8 coil is not limited in particular, such as a single-strand loop figure-8 coil, a multi-strand loop figure-8 coil, a disk-shaped figure-8 coil with a connecting portion for placing a U-shaped magnetic core to limit the width, and the like.

In some alternative embodiments, the overall structure of the coils of the figure-8 coil is not limited, and includes a figure-8 coil with two coils on the same plane, a figure-8 coil with a specific included angle between two coils, and the like.

FIG. 1 is a model diagram for analyzing the effect of a 8-shaped transcranial magnetic stimulation coil on the stimulation effect, wherein the diagram comprises: a soft magnetic core 1, a figure-8 coil 2 and a simplified head model 3. The y-z section is selected to analyze the influence of the magnetic core on the stimulation effect, and the magnetic field intensity and the magnetic field direction in the plane can be adjusted by adjusting the size of the coil. The head model used a 95mm radius sphere to represent the intracranial tissue (represented by the electromagnetic parameters of interstitial fluid) and a 5mm shell outside the sphere to represent the skull. The relative magnetic conductivity, the electric conductivity and the relative dielectric constant of the skull are respectively 0.99, 0.01S/m and 13.50; the relative magnetic permeability, the electric conductivity and the dielectric constant of the tissue fluid are respectively 0.99, 4.0S/m and 80.0. The effect of the change in the coil structure on the stimulation effect was evaluated as a change in the electric field intensity distribution over a 180 ° arc (measurement line) on the side close to the coil in the y-z plane, as shown in fig. 4. Induced electric field intensity E generated right below (theta is 0) by 8-shaped transcranial magnetic stimulation coil₀Maximum, using the electric field intensity E at different positions theta on the measurement line_θ/E₀Evaluating the stimulation accuracy of different coils, increasing E with theta_θ/E₀The faster the decrease, the more accurate the stimulation generated directly below the coil.

As shown in fig. 9, when the symmetry axis of the core coincides with the symmetry axis of the figure-8 coil, i.e., the core is concentric with the figure-8 coil (the center points coincide); as shown in FIG. 5, the 8-shaped coil with the magnetic core can generate stronger induced electric field at the same intracranial position under the condition that the current intensity in the coil is the same. Fig. 9 is a schematic diagram of a magnetic core concentric with the figure-8 coil.

Referring to fig. 6, fig. 6 is a graph of the electric field distribution on the normalized measurement line, and the addition of a magnetic core concentric with the coil has no effect on the stimulation accuracy. As can be seen from FIG. 6, as θ increases, E_θ/E₀First decreasing to 0, and then increasing somewhat. Thus, use of E_θ/E₀Reduced to 0 angle theta (theta)₀) And judging the stimulation precision of different coils. As can be seen from the above, when the magnetic core is concentric with the 8-shaped coil, the magnetic core can reduce the current intensity in the coil without affecting the stimulation effect, but cannot improve the accuracy of the electric field distribution generated in the head model.

Based on the analysis, this embodiment provides an eccentric small-size magnetic core, through the 8 font coil of matching different sizes to reach the purpose that promotes 8 font coil along the amazing precision of magnetic core direction. Under the condition of different combinations of the coil and the magnetic core, compared with the condition that no magnetic core is added or a magnetic core concentric with the coil is added, the magnetic stimulation precision of the transcranial magnetic stimulation coil is obviously improved, as shown in fig. 7. Compared with the 8-shaped coil without the magnetic core or the magnetic core concentric with the 8-shaped coil, the eccentric U-shaped magnetic core provided by the embodiment can be added to obviously reduce theta₀Namely, the stimulation precision of the figure-8 coil is improved. In fig. 7, the square broken line represents the 8-shaped coil without the core, the circular broken line represents the 8-shaped coil with the concentric core, and the triangular broken line represents the 8-shaped coil with the eccentric core, as is apparent from fig. 7, θ corresponding to the eccentric core₀Smaller, i.e. more precise stimulation.

In the process of transcranial magnetic stimulation, alternating current with specific frequency is introduced into the 8-shaped TMS coil (namely the 8-shaped coil), and due to the fact that the frequency of the alternating current is low, the TMS coil can be considered to work in a quasi-static environment, and therefore the magnetic field around the coil can be analyzed through a magnetostatically related theory. Similarly, the magnetization process of a soft magnetic core with high permeability and high saturation magnetization can be magnetized in a quasi-static environment.

Under the action of external magnetic field, the isotropic magnetic material is magnetized, and the magnetic induction intensity after magnetization and the relative magnetic permeability mu of the B magnetic material_rProportional, it can be expressed as:

B＝μ₀μ_rH (1)

here, B is the magnetic induction after magnetization of the material; mu.s₀Is a vacuum magnetic conductivity; mu.s_rIs the relative permeability of the magnetic material; h is the magnetic field strength in the environment where the material is located.

Typically, the permeability of magnetic materials can be very high, such as the μ of silicon steel_rCan reach 7000 to 10000, and the saturation magnetization can reach 1.9 to 2.0T. Therefore, a soft magnetic core with high magnetic conductivity and high saturation magnetization is added in the center of the 8-shaped coil, and strong magnetic induction can be generated under a very small external magnetic field. Therefore, the magnetic material with high magnetic conductivity is added into the 8-shaped coil, the magnetic field distribution around the TMS coil is adjusted, and the stimulation precision of the TMS coil is improved.

Fig. 8 shows distribution of induced electric fields in the front and back of the cranium in the annular 8-shaped TMS coil with the magnetic core. The section is a y-z section in fig. 1, and it can be seen that the area where the electric field intensity generated by the 8-shaped coil in the cranium is the largest is right below the connection position of the 8-shaped coil, the electric field intensity on the surface of the intracranial tissue gradually decreases to 0 along with the increase of the included angle with the coil axis, and then changes to a certain extent along with the continuous increase of the included angle with the coil axis. Since the region where the induced electric field is large is concentrated directly below the 8-shaped coil connection position, the position θ where the electric field intensity directly below the 8-shaped coil decreases from the maximum induced electric field intensity on the coil axis to 0 electric field in the y-z plane can be used₀Judging the stimulation precision of the 8-shaped coils with different structures, and according to the description, determining theta₀Smaller means higher stimulation accuracy of the coil.

Fig. 7 shows the effect of the size of three different types of figure-8 coils calculated using the finite element method on the stimulation accuracy. The three types of coils are respectively: 8-shaped coil without magnetic core and radius R of magnetic core_coreAnd the radius R of the coil_coilMaintenance of R_coil-R_core10mm figure-8 coil (i.e. concentric core), incorporating a U-shaped core of a specific size and R_core＝9mm，L_core＝40mm，H_coreA 23mm soft magnetic core (i.e. an eccentric core). From the results in fig. 7, it can be seen that the stimulation accuracy of the third type coil (with the eccentric magnetic core added) is always better than the first two types, and the larger the coil size is, the more significant the advantage of the third type coil in terms of stimulation accuracy is.

In summary, compared with the existing transcranial magnetic stimulation coil, the transcranial magnetic stimulation coil of the embodiment has the following beneficial effects:

(1) the embodiment provides a transcranial magnetic stimulation coil with an eccentric structure, and the accuracy of stimulation of an 8-shaped coil along the direction of a magnetic core can be improved by matching 8-shaped coils with different sizes.

(2) The embodiment adopts the soft magnetic core, the soft magnetic material has lower coercive force and higher magnetization intensity, and can be magnetized to generate large magnetic flux under a smaller magnetic field, thereby achieving the purpose of changing the magnetic field intensity distribution around the coil.

The present embodiments also provide a transcranial magnetic stimulation device, comprising:

the transcranial magnetic stimulation coil is realized by adopting the 8-shaped transcranial magnetic stimulation coil;

and the power supply is used for providing alternating current with preset frequency for the transcranial magnetic stimulation coil.

The transcranial magnetic stimulation device of the embodiment has a corresponding relationship with the 8-shaped transcranial magnetic stimulation coil, so that the function and effect of the 8-shaped transcranial magnetic stimulation coil are achieved.

The embodiment also provides a transcranial magnetic stimulation system, which comprises a box body and a plurality of transcranial magnetic stimulation devices arranged in the box body.

The transcranial magnetic stimulation system of the embodiment has a corresponding relationship with the 8-shaped transcranial magnetic stimulation coil, so that the function and effect of the 8-shaped transcranial magnetic stimulation coil are achieved.

In the foregoing description of the specification, reference to the description of "one embodiment/example," "another embodiment/example," or "certain embodiments/examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

While the preferred embodiments of the present invention have been illustrated and described, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.