Overlapping stimulation coil assembly and system for biological electromagnetic stimulation

Abstract

The invention discloses an overlapping stimulation coil assembly and system for biological electromagnetic stimulation, and relates to the technical field of biological electromagnetic stimulation. The assembly comprises a lower-layer stimulation coil and an upper-layer stimulation coil which are vertically placed above a biological electromagnetic stimulation target area, the upper-layer stimulation coil and the lower-layer stimulation coil have the same geometric structures similar to semicircular coil structures, and the upper-layer stimulation coil and the lower-layer stimulation coil are arranged in an overlapped mode. The arc part of the lower-layer stimulation coil, the arc part of the upper-layer stimulation coil, the straight long shaft part of the lower-layer stimulation coil and the straight long shaft part of the upper-layer stimulation coil are sequentially arranged from bottom to top, and the upper-layer stimulation coil and the lower-layer stimulation coil are used for being connected with excitation current through different discharging circuits so as to jointly achieve a biological electromagnetic stimulation effect on a target area. Therefore, the focusing property of the stimulation coil can be improved, the intracranial stimulation depth can be enhanced, the adverse effect on a non-target area can be effectively weakened, and the safety of transcranial electromagnetic stimulation treatment can be ensured while the stimulation intensity reaches the stimulation threshold value.

Description

Technical Field

[0001] The present invention belongs to the technical field of bio-electromagnetic stimulation, and in particular relates to an overlapping stimulation coil assembly and system for bio-electromagnetic stimulation. Background Art

[0002] Bio / transcranial electromagnetic stimulation technology was born in the cross-disciplinary field. This technology involves multiple disciplines such as medicine, neuroelectrophysiology and electromagnetism, and has made new contributions in the treatment of neurological diseases and the exploration of brain structure and function. In order to accurately and effectively stimulate the target area in the brain and reduce the side effects of stimulation, the geometric structure design optimization of the stimulation coil has always attracted much attention.

[0003] The most fundamental physical principle of transcranial electromagnetic stimulation is Faraday electromagnetic induction, that is, a rapidly changing excitation current is passed into the stimulation coil so that the time-varying current generates a time-varying magnetic field. The time-varying magnetic field will generate an induced current in the brain tissue, and the induced current will generate an induced electric field to stimulate the nerve tissue inside the brain, causing the neuronal membrane potential to hyperpolarize or depolarize, thereby producing a series of physiological changes. The therapeutic effect of transcranial electromagnetic stimulation depends on a large number of parameters, such as stimulation time, stimulation intensity, duration, and the mode of stimulation current. At present, there are still problems such as weak focusing, insufficient stimulation depth, and single pulse width and frequency parameter adjustment. At the same time, application safety is also a research focus.

[0004] The focusing of the induced electric field of the stimulation coil is a key parameter of transcranial electromagnetic stimulation technology. By designing and optimizing the coil geometry, material selection, spatial arrangement, etc., studying the magnetic field and induced electric field distribution, and determining the stimulation range, the stimulation accuracy of the target area can be effectively improved, the impact on the surrounding non-target areas can be reduced, and the risk of inducing diseases can be reduced. At present, most of the research on stimulation coils is based on the design of the figure-eight coil to improve the focusing of the induced electric field. Transcranial electromagnetic stimulation generates a strong magnetic field through a strong current through the coil, and uses magnetic field gradient control and focusing positioning technology for stimulation. However, due to the complexity of magnetic field gradient control and positioning control, low-frequency stimulation is used to avoid overheating of the coil due to high-frequency stimulation. Therefore, it is of great significance to realize flexible control of multiple stimulation parameters in application.

[0005] The magnetic stimulation coil is an important carrier for realizing transcranial magnetic stimulation and converting time-varying current into specific magnetic field and induced electric field. It is the core of the entire transcranial electromagnetic stimulation and also the difficulty of design. It determines the stimulation intensity, stimulation depth and focus of magnetic stimulation. By improving the stimulation focus of the target area and reducing the stimulation of non-target areas, the occurrence of complications can be reduced. The size, shape, material of the coil, the waveform, intensity and frequency of the stimulation current in the coil, its placement, direction and angle will affect the stimulation effect, specifically the distribution shape, focus, stimulation depth, stimulation position, equipment energy utilization and safety of the induced electric field. Therefore, the design and research of the coil is the key to this technology. At present, the performance of the stimulation coil is mainly improved from multiple aspects such as coil shape structure, coil array design and adding auxiliary materials such as shielding plates.

[0006] In summary, how to provide a new stimulation coil that can induce a more concentrated induced electric field, improve focusing, and have a more balanced stimulation performance, so as to minimize the impact on non-target tissues while effectively stimulating the target point and ensure the effectiveness and safety of transcranial electromagnetic stimulation treatment, is a topic that technical personnel in this field urgently need to study. Summary of the invention

[0007] The purpose of the present invention is to provide an overlapping stimulation coil assembly and a coil overlapping stimulation system for bioelectromagnetic stimulation, so as to solve the problem that traditional stimulation coils have characteristics such as stimulation depth and focusing that cannot be taken into account at the same time, thereby ensuring that the stimulation intensity reaches the stimulation threshold while improving the focusing of the stimulation coil, enhancing the stimulation depth in the skull, effectively reducing the adverse effects on non-target areas, and ensuring the safety of transcranial electromagnetic stimulation treatment.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] In a first aspect, an overlapping stimulation coil assembly for bio-electromagnetic stimulation is provided, comprising a lower stimulation coil and an upper stimulation coil for vertical placement above a target area of ​​bio-electromagnetic stimulation, wherein the lower stimulation coil and the upper stimulation coil have the same geometric structure similar to a semicircular coil structure;

[0010] The lower stimulation coil is arranged overlappingly with the upper stimulation coil, and the arc portion of the lower stimulation coil, the arc portion of the upper stimulation coil, the straight long axis portion of the lower stimulation coil and the straight long axis portion of the upper stimulation coil are arranged in sequence from bottom to top;

[0011] The lower stimulation coil and the upper stimulation coil are used to respectively access the excitation current through different discharge circuits to jointly exert a bio-electromagnetic stimulation effect on the bio-electromagnetic stimulation target area.

[0012] Based on the above invention content, a new stimulation coil design scheme is provided, which can induce a more concentrated induced electric field, improve focusing and have a more balanced stimulation performance, that is, it includes a lower stimulation coil and an upper stimulation coil for vertically placing above a target area of ​​biological electromagnetic stimulation, wherein the upper and lower stimulation coils have the same and similar geometric structure of a semicircular coil structure, the upper and lower stimulation coils are overlapped, and the arc portion of the lower stimulation coil, the arc portion of the upper stimulation coil, the straight long axis portion of the lower stimulation coil and the straight long axis portion of the upper stimulation coil are arranged in sequence from bottom to top, and the upper and lower stimulation coils are arranged in sequence from bottom to top. The excitation coil is used to access the excitation current through different discharge circuits to jointly exert a bio-electromagnetic stimulation effect on the target area. In this way, the mutual influence and superposition of the electromagnetic fields generated by the excitation currents of the upper and lower stimulation coils can produce a strong and focused stimulation effect in the target area, effectively suppressing the negative peak of the coil's induced electric field, while enhancing the aggregation of the induced electric field. Therefore, while ensuring that the stimulation intensity reaches the stimulation threshold, it can improve the focusing of the stimulation coil, enhance the stimulation depth within the skull, and effectively reduce the adverse effects on non-target areas, thereby ensuring the safety of transcranial electromagnetic stimulation treatment and facilitating practical application and promotion.

[0013] In a possible design, the lower stimulation coil or the upper stimulation coil adopts a multi-layer multi-turn coil structure, and the excitation current flows into the lead-in end of the outer straight long axis segment of the multi-layer multi-turn coil structure, and then flows out from the lead-out end of the inner circular arc segment of the multi-layer multi-turn coil structure.

[0014] In a possible design, the lower stimulation coil and the upper stimulation coil are also used to adjust the stimulation intensity and stimulation focus of the bio-electromagnetic stimulation target area through different overlapping angles and / or coil widths.

[0015] In a possible design, the lower stimulation coil and the upper stimulation coil are also used to adjust the degree of directional deviation of the bio-electromagnetic stimulation target area through excitation currents of different magnitudes.

[0016] In a possible design, it also includes an annular shielding plate for wrapping the lower stimulation coil and the upper stimulation coil and having an opening at the bottom.

[0017] In a possible design, the annular shielding plate is formed by stacking thin silicon steel sheets.

[0018] In a second aspect, a coil overlapping stimulation system is provided, comprising a control module, a first charging power module, a second charging power module, a first energy storage capacitor, a second energy storage capacitor, a first discharge switch, a second discharge switch, a first discharge circuit, a second discharge circuit, and an overlapping stimulation coil assembly for bio-electromagnetic stimulation as described in the first aspect, wherein the output end of the control module is electrically connected to the controlled ends of the first charging power module, the second charging power module, the first discharge switch, and the second discharge switch, respectively;

[0019] The positive output end of the first charging power module is electrically connected to one end of the first energy storage capacitor and one end of the first discharge switch, respectively; the other end of the first discharge switch is electrically connected to the positive input end of the first discharge circuit; the negative output end of the first charging power module is electrically connected to the other end of the first energy storage capacitor and the negative input end of the first discharge circuit, respectively; the positive output end of the first discharge circuit is electrically connected to the excitation current introduction end of the lower stimulation coil in the overlapping stimulation coil assembly; and the negative output end of the first discharge circuit is electrically connected to the excitation current lead-out end of the lower stimulation coil;

[0020] The positive output terminal of the second charging power module is electrically connected to one end of the second energy storage capacitor and one end of the second discharge switch, respectively; the other end of the second discharge switch is electrically connected to the positive input terminal of the second discharge circuit; the negative output terminal of the second charging power module is electrically connected to the other end of the second energy storage capacitor and the negative input terminal of the second discharge circuit, respectively; the positive output terminal of the second discharge circuit is electrically connected to the excitation current introduction terminal of the upper stimulation coil in the overlapping stimulation coil assembly; and the negative output terminal of the second discharge circuit is electrically connected to the excitation current lead-out terminal of the upper stimulation coil;

[0021] The first charging power module is used to convert the alternating current into a first direct current and output it under the control of the control module;

[0022] The second charging power module is used to convert the AC power into a second DC power and output it under the control of the control module;

[0023] The control module is used to control the first discharge switch to be turned on when the voltage across the first energy storage capacitor reaches a first expected value, so as to discharge the first energy storage capacitor through the first discharge circuit, and to control the second discharge switch to be turned on when the voltage across the second energy storage capacitor reaches a second expected value, so as to discharge the second energy storage capacitor through the second discharge circuit;

[0024] The first discharge circuit is used to send a first excitation current to the lower stimulation coil when the first energy storage capacitor is discharged;

[0025] The second discharge circuit is used to send a second excitation current to the upper stimulation coil when the second energy storage capacitor is discharged.

[0026] In a possible design, a first clamping diode connected in parallel with the first energy storage capacitor and / or a second clamping diode connected in parallel with the second energy storage capacitor is also included.

[0027] In a possible design, an information acquisition module is also included that is communicatively connected to the control module, wherein the information acquisition module is used to acquire electrophysiological response information generated by the stimulation when the bio-electromagnetic stimulation target area is stimulated, and transmit the electrophysiological response information to the control module for information analysis.

[0028] In a possible design, the first discharge switch or the second discharge switch is a thyristor.

[0029] Beneficial effects of the above scheme:

[0030] (1) The present invention provides a novel stimulation coil design that can induce a more concentrated induced electric field, improve focusing, and have a more balanced stimulation performance, that is, it includes a lower stimulation coil and an upper stimulation coil for vertical placement above a target area of ​​biological electromagnetic stimulation, wherein the upper and lower stimulation coils have the same and similar geometric structure of a semicircular coil structure, the upper and lower stimulation coils are arranged in an overlapping manner, and the arc portion of the lower stimulation coil, the arc portion of the upper stimulation coil, the straight long axis portion of the lower stimulation coil, and the straight long axis portion of the upper stimulation coil are arranged in sequence from bottom to top, and the upper and lower stimulation coils are arranged in a manner that is consistent with the above. The coils are used to access the excitation current through different discharge circuits to jointly exert bio-electromagnetic stimulation on the target area. In this way, the electromagnetic fields generated by the excitation currents of the upper and lower stimulation coils are mutually influenced and superimposed, which can produce a strong and focused stimulation effect in the target area, effectively suppress the negative peak of the coil induced electric field, and enhance the aggregation of the induced electric field. Therefore, while ensuring that the stimulation intensity reaches the stimulation threshold, the focusing of the stimulation coil is improved, the stimulation depth in the skull is enhanced, and the adverse effects on non-target areas are effectively reduced, thereby ensuring the safety of transcranial electromagnetic stimulation treatment and facilitating practical application and promotion.

[0031] (2) Compared with the limitation of the traditional parallel placement of coils, the vertical placement of overlapping coils effectively increases the contact area with the air, which is beneficial to the heat dissipation of the coils during operation;

[0032] (3) Different excitation combinations can achieve directional target shift and focus, while taking into account the improvement of focus depth and stimulation range, and reducing the impact on non-target areas;

[0033] (4) By adding an annular shielding plate formed by stacking thin silicon steel sheets, the eddy current loss inside the overlapping stimulation coil can be effectively reduced, the magnetic energy loss can be reduced, and the focusing effect of the coil can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, 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 invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic diagram of the arrangement relationship between the overlapping stimulation coil assembly for bio-electromagnetic stimulation and the human head provided in an embodiment of the present application, wherein: Figure 1 (a) shows a three-dimensional structural schematic diagram of the arrangement relationship. Figure 1 (b) in the figure shows a schematic diagram of the top view of the arrangement relationship.

[0036] Figure 2 A schematic diagram of the three-dimensional structure of the multi-layer and multi-turn coil structure in the overlapping stimulation coil assembly provided in an embodiment of the present application.

[0037] Figure 3 A side view schematic diagram of the multi-layer and multi-turn coil structure in an overlapping stimulation coil assembly provided in an embodiment of the present application.

[0038] Figure 4 A schematic diagram of the positional relationship between the annular shielding plate and the human head in the overlapping stimulation coil assembly provided in an embodiment of the present application, wherein: Figure 4 (a) shows a three-dimensional structural schematic diagram of the positional relationship, Figure 4 (b) in the figure shows a side view schematic diagram of the positional relationship. Figure 4 (c) in the figure shows a schematic diagram of the top view of the positional relationship.

[0039] Figure 5 This is a comparative example diagram of the stimulation effects based on different coil widths and different overlap angles provided in the embodiment of the present application, wherein: Figure 5 (a) shows an example diagram comparing the stimulation intensity of the intracranial target area generated based on different coil widths and different overlap angles. Figure 5 (b) shows an example comparison of the focal area of ​​the intracranial target region generated based on different coil widths and different overlap angles.

[0040] Figure 6 This is an example diagram comparing the differences in electric field strengths generated by stimulation currents of different sizes provided in an embodiment of the present application.

[0041] Figure 7 This is an example diagram comparing the distribution of the induced electric field generated by the overlapping stimulation coil assembly and the traditional coil provided in the embodiment of the present application, wherein: Figure 7 (a) shows a comparative example of the distribution of the induced electric field generated by the overlapping stimulation coil assembly and the traditional coil along the X test line. Figure 7 (b) shows an example comparison of the distribution of the target area induced electric field strength generated by the overlapping stimulation coil assembly and the traditional coil in the intracranial Z direction.

[0042] Figure 8 This is an example diagram comparing the distribution of the induced electric field generated by the overlapping stimulation coil assembly and the traditional coil in the intracranial target plane provided in the embodiment of the present application, wherein: Figure 8 (a) shows the three-dimensional structure of the traditional figure eight coil and the human skull. Figure 8 (b) shows the distribution of the induced electric field generated by the traditional figure-eight coil on the target plane at a stimulation depth of 20 mm from the scalp vertex. Figure 8 (c) in the figure shows the three-dimensional structure of the overlapping stimulation coil assembly and the human skull. Figure 8 (d) in the figure shows the distribution of the induced electric field generated by the overlapping stimulation coil assembly on the target plane at a stimulation depth of 20 mm from the scalp vertex.

[0043] Fig. 9 This is a schematic diagram of the structure of the coil overlapping stimulation system provided in the embodiment of the present application, wherein: Fig. 9 (a) shows a schematic diagram of the circuit connection relationship between the control module, the first charging power module, the first energy storage capacitor, the first discharge switch, the first discharge circuit and the overlapping stimulation coil assembly in the coil overlapping stimulation system, Fig. 9 (b) shows a schematic diagram of the circuit connection relationship between the control module, the second charging power module, the second energy storage capacitor, the second discharge switch, the second discharge circuit and the overlapping stimulation coil assembly in the coil overlapping stimulation system. DETAILED DESCRIPTION

[0044] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the present invention will be briefly introduced below in combination with the drawings and the description of the embodiments or the prior art. Obviously, the following description of the structure of the drawings is only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention.

[0045] It should be understood that although the terms first and second, etc. may be used herein to describe various objects, these objects should not be limited by these terms. These terms are only used to distinguish one object from another object. For example, a first object can be referred to as a second object, and similarly, a second object can be referred to as a first object without departing from the scope of the exemplary embodiments of the present invention.

[0046] It should be understood that the term "and / or" that may appear in this document is merely a description of the association relationship between associated objects, indicating that there may be three relationships. For example, A and / or B can indicate three situations: A exists alone, B exists alone, or A and B exist at the same time. For another example, A, B and / or C can indicate the existence of any one of A, B and C or any combination of them. The term " / and" that may appear in this document describes another type of association object relationship, indicating that there may be two relationships. For example, A / and B can indicate two situations: A exists alone or A and B exist at the same time. In addition, the character " / " that may appear in this document generally indicates that the previous and next associated objects are in an "or" relationship.

[0047] Example:

[0048] like Figures 1 to 3 As shown, the overlapping stimulation coil assembly provided in the first aspect of this embodiment and used for bio-electromagnetic stimulation includes but is not limited to a lower stimulation coil 1 and an upper stimulation coil 2 for vertically placing above a bio-electromagnetic stimulation target area 100, wherein the lower stimulation coil 1 and the upper stimulation coil 2 have the same and similar geometric structure of a semicircular coil structure; the lower stimulation coil 1 and the upper stimulation coil 2 are arranged overlappingly, and the arc portion of the lower stimulation coil 1, the arc portion of the upper stimulation coil 2, the straight long axis portion of the lower stimulation coil 1 and the straight long axis portion of the upper stimulation coil 2 are arranged in sequence from bottom to top; the lower stimulation coil 1 and the upper stimulation coil 2 are used to respectively access the excitation current through different discharge circuits to jointly exert a bio-electromagnetic stimulation effect on the bio-electromagnetic stimulation target area 100.

[0049] like Figures 1 to 3 As shown, in the specific structure of the overlapping stimulation coil assembly, the lower stimulation coil 1 and the upper stimulation coil 2 respectively adopt a multi-layer multi-turn coil structure, and the excitation current flows into the lead-in end of the outer straight long axis segment of the multi-layer multi-turn coil structure, and then flows out from the lead-out end of the inner arc segment of the multi-layer multi-turn coil structure. The current direction of the excitation current is as shown in FIG. Figure 2As shown by the black solid arrow in . According to the principle of electromagnetic field superposition, the electromagnetic fields generated by the excitation currents (specifically pulse currents) of the upper and lower stimulation coils will affect each other and superimpose each other, thereby producing a strong and focused stimulation effect in the target area, effectively suppressing the negative peak of the coil induced electric field, and enhancing the aggregation of the induced electric field. In addition, the semicircular coil structure specifically includes but is not limited to a semicircular coil structure, a semi-elliptical coil structure, a U-shaped coil structure, and an inverted parabolic coil structure.

[0050] like Figure 2 As shown, the arc portion of the multi-layer multi-turn coil structure is placed vertically close to the human head 200, and this portion will stimulate the intracranial target area (that is, the bio-electromagnetic stimulation target area 100 can be, but is not limited to, for example, this area, such as Figure 1 The distribution and formation of the induced electric field (as shown in the figure) play an important role: Figure 3 As shown in the figure, compared with coils of other shapes, arc-shaped coils have greater advantages in terms of safety and stimulation effect. The degree of curvature of this part will also affect the superposition effect of the intracranial induced electric field. Figure 3 The coil line segment parallel to the X axis is the straight long axis segment, whose length is Rx, and Figure 3 The relative height of the arc segment placed vertically with the scalp from top to bottom and parallel to the Z axis is Rh. These two parameters determine the degree of curvature of the arc part of the coil; the structure of a single stimulation coil is determined by these four main characteristic parameters: the length Rx of the straight long axis segment, the relative height Rh, the coil winding height Rz and the coil width Width. In addition to these four main characteristic parameters, the height difference d of the upper and lower coils will also affect the superposition and focusing of the induced electric field generated by the overlapping coils in the skull. The excitation current of the lower stimulation coil 1 and the upper stimulation coil 2 is as follows: Figure 1 As shown by the black arrow in (a), the excitation current passed through the lower stimulation coil 1 is represented by i1, the excitation current passed through the upper stimulation coil 2 is represented by i2, and the angles between the upper and lower stimulation coils and the Y axis are equal, and the overlapping angle between the lower stimulation coil 1 and the upper stimulation coil 2 is the sum of the angles between the two coils and the Y axis. Let the overlapping angle be α, as shown in Figure 1 In addition, the lower stimulation coil 1 and the upper stimulation coil 2 may overlap at different angles, and the sizes of the two coils may be consistent or inconsistent (coils of different sizes and overlapping angles may have different stimulation effects).

[0051] Preferably, it also includes but is not limited to an annular shielding plate 3 for wrapping the lower stimulation coil 1 and the upper stimulation coil 2 and having an opening 30 at the bottom. Figure 4As shown, overlapping coils can be placed inside the annular shielding plate 3 to form a package to achieve the effect of improving the focusing. Specifically, the annular shielding plate 3 can be, but is not limited to, composed of thin silicon steel sheets stacked together, so that by taking advantage of the characteristics of the silicon steel sheets, not only the resistivity is improved, the loss of eddy current is reduced, but also the focusing effect is improved. Assuming the scalp vertex as the origin, in order to meet the stimulation depth requirements, the XY plane 20 mm below the scalp is taken as the bio-electromagnetic stimulation target area 100, and along the X test line (y = 0, z = -20 mm), the Y test line (x = 0, z = -20 mm), and the Z test line (x = 0, y = 0), the distribution characteristics of the induced electric field space of the target area induction plane are extracted: the induced electric field value generated by the stimulation coil in the brain is called the stimulation intensity, and the maximum value E of the Y component of the induced electric field in the target area is used. ymax Indicates; the stimulation depth indicates the penetration ability of the induced electric field in the brain. The intracranial induced electric field decays from the scalp vertex along the Z test line. When the induced electric field intensity decays to Times E ymax The stimulation depth can be extracted from the Z test line; focusing refers to the ability of the induced electric field to focus on a certain area, which can be used when the maximum induced electric field value E on the target area is greater than ymax of The smaller the ratio, the better the focusing. To evaluate the stimulation effect, the above aspects are generally compared, and by reasonably selecting the above performance indicators, the stimulation effect can be improved to a greater extent.

[0052] Examples of the comparison of stimulation effects based on different coil widths and different overlap angles are as follows: Figure 5 As shown: Take the overlapping coil with specific parameters, whose parameters are Rx = Rh = 40mm, Rz = 6mm, keep d = 1mm, and the excitation current amplitude I 1 =I 2 =5000A, frequency f = 5000Hz remains unchanged. Figure 5 As shown in (a), horizontal observation: for a certain stimulation coil width Width, the stimulation intensity of the intracranial target area decreases with the increase of the stimulation coil overlap angle α. When Width = 12mm, α increases from 60° to 120°, and the stimulation intensity of the intracranial target area decreases from 168.12V / m to 102.36V / m; longitudinal observation: for each certain overlap angle α, the stimulation intensity of the intracranial target area also shows an increasing pattern with the increase of the coil width Width. When α = 90°, Width increases from 9mm to 15mm, and the stimulation intensity of the intracranial target area increases from 108.23V / m to 171.53V / m, with an overall increase of 58.46%. Figure 5As shown in (b), in lateral observation, for a certain stimulation coil width Width, the focal area of ​​the intracranial target area decreases with the increase of the stimulation coil overlap angle α. When Width = 12 mm, α increases from 60° to 120°, and the focal area of ​​the intracranial target area increases from 26.33 cm 2 Reduced to 25.25cm 2 , an overall improvement of 4.1%; longitudinal observation: for each determined overlap angle α, the focal area of ​​the intracranial target area gradually increases with the increase of width Width. When α=90°, Width increases from 9mm to 15mm, and the focal area of ​​the intracranial target area increases from 25.21cm 2 Increased to 26.54cm 2 In summary, the change of the coil width Width and the overlap angle α not only changes the stimulation intensity, but also facilitates the focusing of the stimulation. Thus, preferably, the lower stimulation coil 1 and the upper stimulation coil 2 are also used to adjust the stimulation intensity and the focusing of the bio-electromagnetic stimulation target area 100 through different overlap angles and / or coil widths.

[0053] An example of the difference in electric field strength generated by different stimulation currents is shown below. Figure 6 As shown: take the overlapping coils with specific parameters, whose parameters are Rx=Rh=40mm, Rz=6mm, keep d=1mm, overlap angle α=90°, frequency f=5000Hz unchanged, the excitation current amplitude of the upper stimulation coil 2 remains unchanged and i2=5000A, take the excitation current amplitude i1 of the lower stimulation coil 1 reduced from 5000A to 2500A, the difference Δi corresponding to the two excitation currents = [0kA, 0.5kA, 1kA, 1.5kA, 2kA, 2.5kA]. Figure 6 As shown, with the increase of the difference between the two pulse currents, the intensity of the intracranial induced electric field decreases accordingly, from 141.05 V / m to 97.67 V / m, indicating that with the change of the pulse current amplitude of the upper and lower stimulation coils, the directional shift of the target area can also be effectively achieved. Preferably, the lower stimulation coil 1 and the upper stimulation coil 2 are also used to adjust the degree of directional shift of the bio-electromagnetic stimulation target area 100 by means of excitation currents of different sizes.

[0054] An example of a comparison of the induced electric field distribution generated by the overlapping stimulation coil assembly and the traditional coil is shown below. Figure 7 As shown: When the excitation current amplitude is 5000A and the total number of coil turns n=8, Figure 7 (a) in the figure shows that compared with the traditional figure eight coil, the overlapping coil effectively suppresses the negative peak of the induced electric field, making it more advantageous in generating a more concentrated induced electric field. Figure 7(b) in the figure shows that under the same stimulation conditions, when reaching the same stimulation depth point a, the attenuation of the induced electric field of the overlapping coil is significantly less than that of the traditional figure-eight coil. Assuming 50V / m is the minimum stimulation intensity required to reach the nerve stimulation threshold, it can be seen that the stimulation depth point b of the traditional figure-eight coil is less than the stimulation depth point c of the overlapping stimulation coil, that is, the overlapping coil can take into account the improvement of the stimulation depth.

[0055] An example of a comparison of the induced electric field distribution generated by the overlapping stimulation coil assembly and the traditional coil in the intracranial target plane is shown below. Figure 8 As shown: When the excitation current amplitude is 5000A, the inner diameter of the coil is 34mm, and the total number of turns is n=8, Figure 8 As shown in (a) and (b), the stimulation intensity of the figure eight coil is E max =169.22V / m, stimulation area is 27.27cm 2 When the excitation current amplitude of the upper and lower stimulation coils is 5000A, Rx = Rh = 40mm, Rz = 6mm, d = 1mm, overlap angle α = 90°, and the total number of turns n = 8, Figure 8 As shown in (c) and (d) in the figure, the stimulation intensity of the overlapping coil is E ymax =144.74V / m, stimulation area is 24.44cm 2 It can be seen that under the premise of reaching the threshold of nerve stimulation, the induced electric field distribution generated by the overlapping coil is more ideal than that of the traditional figure-eight coil, and its focusing is improved by 10.4%, that is, the stimulation area is effectively reduced while the stimulation depth is increased.

[0056] like Fig. 9As shown, the second aspect of this embodiment provides a coil overlapping stimulation system using the overlapping stimulation coil assembly described in the first aspect, including but not limited to a control module AD1, a first charging power module DC1, a second charging power module DC2, a first energy storage capacitor C1, a second energy storage capacitor C2, a first discharge switch K1, a second discharge switch K2, a first discharge circuit FD1, a second discharge circuit FD2 and the overlapping stimulation coil assembly for bio-electromagnetic stimulation as described in the first aspect, wherein the output end of the control module AD1 is electrically connected to the controlled ends of the first charging power module DC1, the second charging power module DC2, the first discharge switch K1 and the second discharge switch K2 respectively; The positive output end of the first charging power module DC1 is electrically connected to one end of the first energy storage capacitor C1 and one end of the first discharge switch K1, respectively; the other end of the first discharge switch K1 is electrically connected to the positive input end of the first discharge circuit FD1; the negative output end of the first charging power module DC1 is electrically connected to the other end of the first energy storage capacitor C1 and the negative input end of the first discharge circuit FD1, respectively; the positive output end of the first discharge circuit FD1 is electrically connected to the excitation current introduction end of the lower stimulation coil 1 in the overlapping stimulation coil assembly, and the negative output end of the first discharge circuit FD1 is electrically connected to the excitation current lead-out end of the lower stimulation coil 1; the second charging power module DC1 is electrically connected to the positive output end of the first energy storage capacitor C1 and the negative input end of the first discharge circuit FD1, respectively; the positive output end of the first discharge circuit FD1 is electrically connected to the excitation current introduction end of the lower stimulation coil 1 in the overlapping stimulation coil assembly, and the negative output end of the first discharge circuit FD1 is electrically connected to the excitation current lead-out end of the lower stimulation coil 1; The positive output end of the module DC2 is electrically connected to one end of the second energy storage capacitor C2 and one end of the second discharge switch K2, respectively; the other end of the second discharge switch K2 is electrically connected to the positive input end of the second discharge circuit FD2; the negative output end of the second charging power module DC2 is electrically connected to the other end of the second energy storage capacitor C2 and the negative input end of the second discharge circuit FD2, respectively; the positive output end of the second discharge circuit FD2 is electrically connected to the excitation current introduction end of the upper stimulation coil 2 in the overlapping stimulation coil assembly; the negative output end of the second discharge circuit FD2 is electrically connected to the excitation current lead-out end of the upper stimulation coil 2; the first charging power module DC1 is used The control module AD1 is used to convert the AC power into the first DC power and output it under the control of the control module AD1; the second charging power supply module DC2 is used to convert the AC power into the second DC power and output it under the control of the control module AD1; the control module AD1 is used to control the first discharge switch K1 to be turned on when the voltage across the first energy storage capacitor C1 reaches a first expected value, so as to discharge the first energy storage capacitor C1 through the first discharge circuit FD1, and control the second discharge switch K2 to be turned on when the voltage across the second energy storage capacitor C2 reaches a second expected value, so as to discharge the second energy storage capacitor C2 through the second discharge circuit FD2;The first discharge circuit FD1 is used to send a first excitation current to the lower stimulation coil 1 when the first energy storage capacitor C1 is discharged; the second discharge circuit FD2 is used to send a second excitation current to the upper stimulation coil 2 when the second energy storage capacitor C2 is discharged.

[0057] like Fig. 9 As shown, in the specific structure of the coil overlapping stimulation system, the control module is used as the system control center, which can adjust the excitation current of the upper and lower stimulation coils within a certain range to shift the stimulation area to the left or right, and it can control the charging power module and the discharge switch to achieve the purpose of repeated stimulation, and it can be specifically implemented by a microcontroller of the STM32F105 series. In addition, the aforementioned first charging power module DC1, the second charging power module DC2, the first energy storage capacitor C1, the second energy storage capacitor C2, the first discharge switch K1, the second discharge switch K2, the first discharge circuit FD1 and the second discharge circuit FD2 can all be implemented using existing devices or corresponding circuits. Preferably, it also includes a first clamping diode D1 connected in parallel with the first energy storage capacitor C1 and / or a second clamping diode D2 connected in parallel with the second energy storage capacitor C2, such as Fig. 9 As shown, the clamping of the diode can be used to prepare for subsequent stimulation. Preferably, an information acquisition module SC1 is also included that is communicatively connected to the control module AD1, wherein the information acquisition module SC1 is used to acquire electrophysiological response information generated by the stimulation when the bio-electromagnetic stimulation target area 100 is stimulated, and transmit the electrophysiological response information to the control module for information analysis. In addition, the first discharge switch K1 or the second discharge switch K2 preferably uses a thyristor to take advantage of its low loss and save energy.

[0058] The working process, working details and technical effects of the aforementioned system provided in the second aspect of this embodiment can be referred to the overlapping stimulation coil assembly described in the first aspect, and will not be described in detail here.

[0059] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An overlapping stimulation coil assembly for bio-electromagnetic stimulation, characterized in that: The invention comprises a lower stimulation coil (1) and an upper stimulation coil (2) for vertically placing above a bio-electromagnetic stimulation target area (100), wherein the lower stimulation coil (1) and the upper stimulation coil (2) have the same geometric structure similar to a semicircular coil structure; The lower stimulation coil (1) and the upper stimulation coil (2) are arranged in an overlapping manner, and the arc portion of the lower stimulation coil (1), the arc portion of the upper stimulation coil (2), the straight long axis portion of the lower stimulation coil (1) and the straight long axis portion of the upper stimulation coil (2) are arranged in sequence from bottom to top; The lower stimulation coil (1) and the upper stimulation coil (2) are used to respectively access the excitation current through different discharge circuits to jointly exert a bio-electromagnetic stimulation effect on the bio-electromagnetic stimulation target area (100).

2. The overlapping stimulation coil assembly according to claim 1, characterized in that: The lower stimulation coil (1) or the upper stimulation coil (2) adopts a multi-layer multi-turn coil structure, and the excitation current flows into the lead-in end of the outer straight long axis segment of the multi-layer multi-turn coil structure, and then flows out from the lead-out end of the inner circular arc segment of the multi-layer multi-turn coil structure.

3. The overlapping stimulation coil assembly according to claim 1, characterized in that: The lower stimulation coil (1) and the upper stimulation coil (2) are also used to adjust the stimulation intensity and stimulation focus of the bio-electromagnetic stimulation target area (100) through different overlapping angles and / or coil widths.

4. The overlapping stimulation coil assembly according to claim 1, characterized in that: The lower stimulation coil (1) and the upper stimulation coil (2) are also used to adjust the degree of directional deviation of the bio-electromagnetic stimulation target area (100) through excitation currents of different magnitudes.

5. The overlapping stimulation coil assembly according to claim 1, characterized in that: It also includes an annular shielding plate (3) for wrapping the lower stimulation coil (1) and the upper stimulation coil (2) and having an opening (30) at the bottom.

6. The overlapping stimulation coil assembly according to claim 5, characterized in that: The annular shielding plate (3) is formed by stacking thin silicon steel sheets.

7. A coil overlap stimulation system, characterized in that: The invention comprises a control module (AD1), a first charging power module (DC1), a second charging power module (DC2), a first energy storage capacitor (C1), a second energy storage capacitor (C2), a first discharge switch (K1), a second discharge switch (K2), a first discharge circuit (FD1), a second discharge circuit (FD2), and an overlapping stimulation coil assembly for bio-electromagnetic stimulation according to any one of claims 1 to 6, wherein the output end of the control module (AD1) is electrically connected to the controlled ends of the first charging power module (DC1), the second charging power module (DC2), the first discharge switch (K1), and the second discharge switch (K2), respectively; The positive output end of the first charging power module (DC1) is electrically connected to one end of the first energy storage capacitor (C1) and one end of the first discharge switch (K1), the other end of the first discharge switch (K1) is electrically connected to the positive input end of the first discharge circuit (FD1), the negative output end of the first charging power module (DC1) is electrically connected to the other end of the first energy storage capacitor (C1) and the negative input end of the first discharge circuit (FD1), the positive output end of the first discharge circuit (FD1) is electrically connected to the excitation current introduction end of the lower stimulation coil (1) in the overlapping stimulation coil assembly, and the negative output end of the first discharge circuit (FD1) is electrically connected to the excitation current lead-out end of the lower stimulation coil (1); The positive output end of the second charging power module (DC2) is electrically connected to one end of the second energy storage capacitor (C2) and one end of the second discharge switch (K2), the other end of the second discharge switch (K2) is electrically connected to the positive input end of the second discharge circuit (FD2), the negative output end of the second charging power module (DC2) is electrically connected to the other end of the second energy storage capacitor (C2) and the negative input end of the second discharge circuit (FD2), the positive output end of the second discharge circuit (FD2) is electrically connected to the excitation current introduction end of the upper stimulation coil (2) in the overlapping stimulation coil assembly, and the negative output end of the second discharge circuit (FD2) is electrically connected to the excitation current lead-out end of the upper stimulation coil (2); The first charging power supply module (DC1) is used to convert alternating current into first direct current and output it under the control of the control module (AD1); The second charging power supply module (DC2) is used to convert the alternating current into a second direct current and output it under the control of the control module (AD1); The control module (AD1) is used for controlling the first discharge switch (K1) to be turned on when the voltage across the first energy storage capacitor (C1) reaches a first expected value, so as to discharge the first energy storage capacitor (C1) through the first discharge circuit (FD1), and for controlling the second discharge switch (K2) to be turned on when the voltage across the second energy storage capacitor (C2) reaches a second expected value, so as to discharge the second energy storage capacitor (C2) through the second discharge circuit (FD2); The first discharge circuit (FD1) is used to send a first excitation current to the lower stimulation coil (1) when the first energy storage capacitor (C1) is discharged; The second discharge circuit (FD2) is used to send a second excitation current to the upper stimulation coil (2) when the second energy storage capacitor (C2) is discharged.

8. The coil overlapping stimulation system according to claim 7, characterized in that: It also includes a first clamping diode (D1) connected in parallel with the first energy storage capacitor (C1) and / or a second clamping diode (D2) connected in parallel with the second energy storage capacitor (C2).

9. The coil overlapping stimulation system according to claim 7, characterized in that: It also includes an information acquisition module (SC1) communicatively connected to the control module (AD1), wherein the information acquisition module (SC1) is used to acquire electrophysiological response information generated by the stimulation when the bio-electromagnetic stimulation target area (100) is stimulated, and transmit the electrophysiological response information to the control module for information analysis.

10. The overlapping coil stimulation system according to claim 7, characterized in that: The first discharge switch (K1) or the second discharge switch (K2) is a thyristor.

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