High-focusing-degree splayed magnetic stimulation coil

Abstract

The utility model discloses a high-focusing-degree splayed magnetic stimulation coil. The high-focusing-degree splayed magnetic stimulation coil comprises an upper coil layer and a lower coil layer, wherein the upper coil layer and the lower coil layer are formed by winding cables; by taking the center axis of the coil as a boundary, each coil layer comprises left coils and right coils which are of spiral curve structures, and each circle of cable of the two left coils and each circle of cable of the two right coils are overlapped with each other; in each circle of cable of the left coil and the right coil, the distance between the cables close to one side of the coil middle shaft is smaller than that between the cables far away from one side of the coil middle shaft; in the upper coil layer, the tail ends of the outermost ring cables of the left coil and the right coil are respectively a current input end and a current output end; in the lower coil layer, the tail ends of the outermost rings of cables of the left coil and the right coil are connected with each other; the tail ends of the innermost rings of cables of the two layers of left coils are connected with each other, and the tail ends of the innermost rings of cables of the two layers of right coils are connected with each other. According to the utility model, the gathering degree and the stimulation depth of the coil can be improved, and the stimulation to the non-target area position can be weakened at the same time.

Description

Technical Field

[0001] The utility model belongs to the field of transcranial magnetic stimulation, in particular to a high-focus figure-eight magnetic stimulation coil. Background Art

[0002] Repetitive transcranial magnetic stimulation (rTMS) is used for treatment mainly by changing its stimulation frequency to achieve the purpose of exciting or inhibiting local cerebral cortical function. High-frequency, high-intensity rTMS can produce a sum of excitatory postsynaptic potentials, leading to abnormal excitation of the nerves at the stimulated site, while low-frequency stimulation has the opposite effect, treating diseases by bidirectionally regulating the balance between the excitatory and inhibitory functions of the brain. The local nerves stimulated by rTMS affect the functions of multiple parts through the connection and interaction between neural networks; different intensities, frequencies, stimulation sites, and coil directions are required to achieve good therapeutic effects for different patients' brain function conditions.

[0003] The magnetic stimulation coil is the load of the pulse current generating circuit and is made of a wire with low resistivity. When the shape of the coil is different, the distribution of the induced electric field generated will also be different, which will directly affect the stimulation intensity, stimulation depth, focus, stimulation angle, etc. In order to accurately and effectively stimulate the target, high requirements are placed on the intensity, stimulation depth, focus and stimulation direction of the electromagnetic field generated by the coil. High focus can narrow the stimulation range, enhance the targeted stimulation, and reduce the impact on non-target tissues. Sufficient stimulation depth can ensure that the magnetic stimulation still has a certain stimulation intensity on the tissue below the surface of the human body, so that the intracranial nerve tissue can be effectively stimulated.

[0004] With the development of transcranial magnetic stimulation technology, the coils currently used in the market have become more diverse, mainly circular, figure-eight-shaped, figure-eight-derivative, H-shaped, etc.; the circular coil has a simple structure and is easy to use, but has a large stimulation range and poor focusing; the peak value of the induced electric field of the figure-eight coil (such as publication number: CN117116592A) is distributed at the junction of the two coils, and its focusing degree is greatly improved compared with the circular coil, but the stimulation depth is also limited by the coil structure. Utility Model Content

[0005] The utility model provides a high-focus figure-eight-shaped magnetic stimulation coil, which can improve the concentration and stimulation depth of the coil and reduce the stimulation to non-target areas.

[0006] A high-focus figure-eight magnetic stimulation coil comprises an upper coil layer and a lower coil layer formed by winding cables, with the central axis of the coil as a dividing line, each coil layer comprises a left coil and a right coil of a spiral curve structure, and each turn of the cable of the two left coils and each turn of the cable of the two right coils are superimposed on each other;

[0007] In each circle of the left coil and the right coil, the distance between the cables on the side close to the central axis of the coil is smaller than the distance between the cables on the side far from the central axis of the coil;

[0008] In the upper coil layer, the outermost cable ends of the left coil and the right coil are the current input end and the current output end respectively; in the lower coil layer, the outermost cable ends of the left coil and the right coil are connected to each other; the innermost cable ends of the two layers of left coils are connected to each other, and the innermost cable ends of the two layers of right coils are connected to each other.

[0009] Furthermore, the distance between the innermost circle center of the left coil and the innermost circle center of the right coil is 65-80 mm.

[0010] Furthermore, in each circle of the left coil and the right coil, the cable spacing on the side close to the central axis of the coil is 0 to 1.5 mm.

[0011] Furthermore, the angle between the plane of the left coil and the plane of the right coil is 150° to 175°, so that the coil has a certain taper to achieve better focusing.

[0012] Furthermore, the cable thickness is 2 to 4 mm.

[0013] Furthermore, an insulating film is arranged between the upper coil layer and the lower coil layer to increase insulation between the upper and lower coil layers.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The coil of the present invention adopts double-layer coil superposition to enhance the induced magnetic field strength on each side; at the same time, each layer adopts an eccentric involute winding method (specifically, a spiral curve structure winding, and the cable spacing on the side close to the coil center axis is smaller than the cable spacing on the side away from the coil center axis), so that the cables close to the coil center axis are more concentrated, and the cables away from the center axis are more sparsely wound, so as to reduce stimulation to non-target areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram of the overall structure of a high-focus figure-eight magnetic stimulation coil of the utility model;

[0017] Figure 2 This is a schematic diagram of the lower coil in the utility model;

[0018] Figure 3 This is a schematic diagram of the upper coil in the utility model;

[0019] Figure 4 It is a schematic diagram of the taper of the coil in the utility model;

[0020] Figure 5 This is a schematic diagram of the three-dimensional electric field spatial distribution of the coil of the utility model;

[0021] Figure 6 It is a schematic diagram of two-dimensional equivalent distribution of coil simulation of the utility model.

[0022] In the figure: 10 - lower coil layer, 20 - upper coil layer, 101 - current input terminal, 102 - current output terminal. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be pointed out that the embodiments described below are intended to facilitate the understanding of the present invention and do not have any limiting effect on the present invention.

[0024] like Figure 1 As shown, a high-focus figure-eight magnetic stimulation coil includes an upper coil layer 20 and a lower coil layer 10 wound by cables. The upper coil layer 20 is a far treatment surface coil, and the lower coil layer 10 is a near treatment surface coil. An insulating film is arranged between the upper coil layer 20 and the lower coil layer 10.

[0025] Taking the coil center axis as the dividing line, each coil layer includes a left coil and a right coil of a spiral curve structure, and each turn of the cables of the two left coils and each turn of the cables of the two right coils are superimposed on each other. In the upper coil layer, the ends of the outermost turns of the cables of the left coil and the right coil are the current input end 101 and the current output end 102, respectively.

[0026] like Figure 2 As shown, the lower coil layer 10 is a point-symmetrical structure, divided into two left and right coils, both coils adopt an eccentric involute winding method (specifically a spiral curve structure, and the cable spacing on the side close to the coil center axis is smaller than the cable spacing on the side away from the coil center axis). The distance H between the innermost circle center of the left coil and the innermost circle center of the right coil is 65-80 mm.

[0027] like Figure 2 As shown in the right coil, the radii of the six semicircles corresponding to the involute at the lower part of the horizontal axis are R1, R3, R5, R7, R9, and R11 respectively; the radii of the six semicircles corresponding to the involute at the upper part of the horizontal axis are R2, R4, R6, R8, R10, and R12 respectively; the distance between the centers of the upper and lower semicircles is Δr; the maximum axis spacing of the cables close to the center axis of the coil is L3 = R2-R1 = R4-R3 = ..., and the maximum axis spacing of the cables away from the center axis of the coil is L2 = R3-R2 = R5-R4 = ...; the cable thickness is L1 = 2 to 4 mm; the cable gap F2 = 0 to 1.5 mm close to the center axis of the coil; and the cable gap F1 = L2-L1 away from the center axis of the coil. Similarly, since the left coil and the right coil are point-symmetrical structures, the shape structure of the left coil also conforms to the above description.

[0028] like Figure 2 and Figure 3As shown, the upper coil layer 20 structure is superimposed on the lower coil layer 10, and the innermost cable end point a of the left coil in the lower coil layer 10 is connected to the innermost cable end point a' of the left coil in the upper coil layer 20, and the winding is still wound in a clockwise manner; similarly, the innermost cable end point b of the right coil in the lower coil layer 10 is connected to the innermost cable end point b' of the right coil in the upper coil layer 20. The current i enters from the current input terminal 101 and flows out from the current output terminal 102.

[0029] like Figure 4 As shown, after the coil is wound as described above, the coil will be formed into a conical coil with a certain angle α=150-175° in the mold to achieve better focusing.

[0030] like Figure 5 As shown, it is a schematic diagram of the three-dimensional electric field spatial distribution of the coil of the utility model. It can be seen that the induced electric field spatial distribution thereof shows its spatial three-dimensional electric field distribution, showing that the induced electric field intensity is strongest at the center of the coil and rapidly weakens from the center outward.

[0031] like Figure 6 As shown, it is a two-dimensional equivalent diagram of the simulation results of the coil of the utility model. It can be seen that the two-dimensional equivalent diagram on the cross section below the coil further proves that the induced electric field intensity in the center is the strongest, and the electric field energy decays rapidly outward, proving the high focusing property of the coil.

[0032] In summary, the coil of the utility model adopts double-layer coil superposition to enhance the strength of the induced magnetic field on each side; at the same time, each layer adopts an eccentric involute winding method, so that the cables are more concentrated near the central axis of the coil and more sparsely wound away from the part, so as to reduce the stimulation to the non-target area; similarly, a certain taper is adopted to achieve better focusing.

[0033] The embodiments described above provide a detailed description of the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, supplements and equivalent substitutions made within the scope of the principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A high-focus figure-eight magnetic stimulation coil, characterized in that: It includes an upper coil layer and a lower coil layer wound by cables; with the central axis of the coil as a dividing line, each coil layer includes a left coil and a right coil of a spiral curve structure, and each turn of the cable of the two left coils and each turn of the cable of the two right coils are superimposed on each other; In each circle of the left coil and the right coil, the distance between the cables on the side close to the central axis of the coil is smaller than the distance between the cables on the side far from the central axis of the coil; In the upper coil layer, the outermost cable ends of the left coil and the right coil are the current input end and the current output end respectively; in the lower coil layer, the outermost cable ends of the left coil and the right coil are connected to each other; the innermost cable ends of the two layers of left coils are connected to each other, and the innermost cable ends of the two layers of right coils are connected to each other.

2. The high-focus figure-eight magnetic stimulation coil according to claim 1, characterized in that: The distance between the innermost circle center of the left coil and the innermost circle center of the right coil is 65-80 mm.

3. The high-focus figure-eight magnetic stimulation coil according to claim 1, characterized in that: In each circle of the left coil and the right coil, the cable spacing on the side close to the central axis of the coil is 0 to 1.5 mm.

4. The high-focus figure-eight magnetic stimulation coil according to claim 1, characterized in that: The angle between the plane of the left coil and the plane of the right coil is 150° to 175°.

5. The high-focus figure-eight magnetic stimulation coil according to claim 1, characterized in that: The cable thickness is 2 to 4 mm.

6. The high-focus figure-eight magnetic stimulation coil according to claim 1, characterized in that: An insulating film is arranged between the upper coil layer and the lower coil layer.

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