WO2023000625A1

WO2023000625A1 - Transcranial magnetic stimulation coil and helmet for deep and precise magnetic stimulation

Info

Publication number: WO2023000625A1
Application number: PCT/CN2022/071107
Authority: WO
Inventors: 吴潇; 张隽毅; 林彦辰
Original assignee: 杭州米福科技有限公司
Priority date: 2021-07-23
Filing date: 2022-01-10
Publication date: 2023-01-26
Also published as: CN113559417B; CN113559417A

Abstract

Disclosed are a transcranial magnetic stimulation coil and a helmet for deep and precise magnetic stimulation. The transcranial magnetic stimulation coil comprises a coil fixing member and a D-O two-way coil which is fixed by means of the coil fixing member, the D-O two-way coil comprises a D-shaped coil and an O-shaped coil which are arranged asymmetrically, and two ends of the D-shaped coil and two ends of the O-shaped coil are connected to a current output device after passing through the coil fixing member. The D-shaped coil is arranged inside the O-shaped coil, a position where the D-shaped coil and the O-shaped coil intersect is tightly attached to the upper part of the O-shaped coil, and the intersection area forms a target area. The current output device outputs a reference current for the D-shaped coil which provides a reference magnetic field distribution intensity and direction. The current output device provides an adjusting current for the O-shaped coil which adjusts the overall magnetic field distribution intensity and direction of the D-O two-way coil. The present invention can be used to perform stimulation treatment on the target area more safely while minimizing the stimulation to non-target areas.

Description

A transcranial magnetic stimulation coil and helmet for deep precise magnetic stimulation

technical field

The invention belongs to the field of medical equipment, and in particular relates to a transcranial magnetic stimulation coil and a helmet for deep precise magnetic stimulation.

Background technique

Transcranial magnetic stimulation (Transcranial Magnetic Stimulation, TMS) is the use of time-varying pulse electromagnetic field induced electric field to act on the central nervous system of the brain, changing the membrane potential of the cerebral cortex nerve cells, affecting the metabolism and neural electrical activity in the brain, thus causing a series of A therapeutic method in the field of brain nerves based on physiological and biochemical reactions. Existing transcranial magnetic stimulation devices are mainly planar circular coils and planar 8-shaped coils.

For example, the Chinese patent document with the publication number CN112582159A discloses a stimulation coil for magnetic stimulation, including a coil body, a coil hole is provided in the middle of the coil body, and the coil body includes an upper layer coil and a lower layer coil, and the upper layer Both the coil and the lower coil are tightly wound by the same wire tube, the upper coil and the lower coil are connected through a transition wire tube at the outer edge of the coil hole, and the wire tube of the outer coil of the upper coil is bent A section is folded to form a current input pipeline, and the outer coil of the lower coil is bent to extend a section to form a current output pipeline, and the bend of the current output pipeline is close to the edge of the current input pipeline. bend.

The Chinese patent document with the publication number CN109621211A discloses a locally enhanced figure-eight transcranial magnetic stimulation coil, by processing the equal-thickness figure-eight transcranial magnetic stimulation coil into a concave shape in the central area of the back of the coil, and keeping the coil The surface of the frontal coil is on a plane, so that the equivalent electric current of the coil in the central area is closer to the stimulation area, thereby generating a magnetic field pulse stronger than that of the iso-thick structure in the central area, while affecting other areas outside the central area. The influence of the regional magnetic field pulse is negligible, so that the locally enhanced figure-of-eight transcranial magnetic stimulation coil has better focus and a more concentrated stimulation range.

However, the stimulation depth of existing transcranial magnetic stimulation equipment is generally shallow. Taking the planar 8-shaped coil as an example, its focal area is small, and the stimulation depth is about 20mm below the surface of the coil, which cannot stimulate the sulcus of the cerebral cortex. It is also unable to stimulate the subcortical tissues such as the amygdala and hippocampus.

In order to overcome the problems of insufficient focal depth and small focal area of existing coils, it is urgent to design a new transcranial magnetic stimulation coil.

Contents of the invention

The invention provides a transcranial magnetic stimulation coil and a helmet for deep precise magnetic stimulation, which can safely stimulate the target area under the premise that the stimulation intensity of the non-target area is as small as possible.

A transcranial magnetic stimulation coil for deep precise magnetic stimulation, comprising a coil fixing part and a DO double-circuit coil fixed by the coil fixing part, and the DO double-circuit coil includes an asymmetrically arranged D-shaped coil and an O-shaped coil. Coil, the two ends of the D-shaped coil and the O-shaped coil are connected to the current output device after passing through the coil fixture;

The D-shaped coil is arranged inside the O-shaped coil, and the D-shaped coil is close to the upper part of the O-shaped coil at the position where it intersects with the O-shaped coil, and the intersecting area constitutes the target target area;

The current output device outputs a reference current for the D-shaped coil to provide the reference magnetic field distribution strength and direction; the current output device provides an adjustment current for the O-shaped coil to adjust the overall magnetic field distribution strength and direction of the DO dual-circuit coil.

Preferably, the DO double-circuit coil is provided with a target indicator for determining the stimulation point in the target area, and an observation hole is provided on the target indicator.

Preferably, both the D-shaped coil and the O-shaped coil are formed by a plurality of wires arranged in parallel; the distance between the multiple wires of the D-shaped coil in the target area is less than 3 mm, and the distance between the non-target areas is greater than 10 mm, less than 20mm; Among them, the transition area between 3mm and 10mm is the transition area.

The multiple wires of the O-shaped coil are closely attached to each other, and the adjacent distance is less than 3mm.

Preferably, the target area has an area of 10-13 square centimeters.

Further, the magnetic induction intensity test of the transcranial magnetic stimulation coil needs to be carried out during the production process, so as to fine-tune the structure of the transcranial magnetic stimulation coil, including the following steps:

(1) Make a human skull model cut into three pieces, the corresponding anatomical positions of each piece are the hair and scalp, the surface of the cerebral cortex, and the superficial cortex of the skull;

(2) Each piece is set with a test point every 1mm on the coordinate axis of the horizontal plane projection, which is used for magnetic induction intensity test positioning and repeated testing. The test points are in a state of central symmetry, and each test point can be one-to-one correspondence;

(3) Simulate the treatment process so that the coil of the present invention is closely joined with the human skull model made in step (1);

(4) Put the three-phase Hall effect probe close to the mark point to be stimulated on the human skull model, control the current output device to output pulses to the DO dual-circuit coil, and read the original magnetic induction through an oscilloscope connected to the three-phase Hall effect probe Intensity waveform, the magnetic induction intensity value of the test point is obtained after calculation;

(5) Using the method of step (4), the three-phase Hall effect probe is successively brought close to each test point on the human skull model to obtain the magnetic induction value of each test point;

(6) Draw the magnetic induction distribution map according to the magnetic induction intensity values of all test points, and fine-tune the shape of the transcranial magnetic stimulation coil according to the output pulse intensity and the magnetic induction distribution map.

Further, in step (1), the thicknesses of the human skull models cut into three pieces are 2mm, 13mm and 18mm respectively.

The present invention also provides a magnetic stimulation helmet, which includes a helmet body and the above-mentioned transcranial magnetic stimulation coil; the transcranial magnetic stimulation coil is arranged inside the helmet body;

Wherein, the D-shaped coil is close to the inner wall surface of the helmet body, and is used to closely fit the head during use; the O-shaped coil is only close to the inner wall surface of the helmet body in the target area, and other areas They are all away from the inner wall surface of the helmet body; the current output device is arranged on the helmet body and connected with the supporting host.

Preferably, the helmet body is provided with an observation window, and the observation window is directly opposite to the observation hole of the target indicator on the target area. During use, place the magnetic stimulation helmet on the patient's head, move the helmet, and observe through the observation window so that the observation hole of the target indicator on the coil coincides with the auxiliary mark point on the positioning cap.

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

1. The transcranial magnetic stimulation coil of the present invention adopts a DO double-circuit coil, and the D-shaped coil is located on the upper layer, which mainly plays a supporting role and provides reference stimulation; the weight of the coil and the helmet can be dispersed, so that the contact part of the patient's head will not feel sick. In the target area, the line-to-line spacing is small, so that the magnetic field lines are focused on the target area and the impact on the non-target area is reduced; the dense wires in the target area give the target area a basic intensity and direction of the magnetic field distribution. The O-shaped coil is located in the lower layer, and mainly plays the role of adjusting the magnetic induction intensity and direction. On the basis of the basic magnetic field distribution provided by the D coil, by changing the position and current intensity of the O segment coil, the magnetic field distribution intensity and direction after the DO coil is combined Adjust to match the intended design.

2. The induced magnetic field of the present invention is asymmetrically distributed, and the magnetic field at the non-target position on the coil surface is relatively small and within a safe range. Focusing at the depth target, the focusing range is wider than that of the figure-eight coil, and the induced electric field generated at a lower current output intensity can be higher than the action potential threshold of most patients' nerve cells. Under the premise that the same depth reaches a certain intensity of the induced magnetic field, the present invention requires less stimulation current than the 8-shaped coil, less stimulation to the human body contact part on the coil surface, a larger stimulation range to the target area, and stronger fault tolerance. During the treatment process, the center of gravity of the coil and the matching helmet is basically kept on the same axis as the center of gravity of the human body, which can reduce the pull of gravity on the coil and cause the shift of the focus area.

Description of drawings

Fig. 1 is the structural diagram of transcranial magnetic stimulation coil in the present invention;

Fig. 2 is a schematic diagram of another angle of the transcranial magnetic stimulation coil in the present invention;

Fig. 3 is the schematic diagram of magnetic stimulation helmet in the present invention;

Fig. 4 is the magnetic induction distribution figure of hair and scalp part during the test of the embodiment of the present invention;

Fig. 5 is the distribution diagram of the magnetic induction intensity of the skull and meninges during the test of the embodiment of the present invention;

Fig. 6 is a distribution diagram of the magnetic induction intensity of part of the cerebral cortex during the test of the embodiment of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be noted that the following embodiments are intended to facilitate the understanding of the present invention, but do not limit it in any way.

As shown in Figures 1 and 2, a transcranial magnetic stimulation coil for deep precise magnetic stimulation includes a coil holder 1 and a DO dual-circuit coil fixed by the coil holder, and the DO dual-circuit coil includes an asymmetric arrangement The D-shaped coil 2 and the O-shaped coil 3. The two ends of the D-shaped coil 2 and the O-shaped coil 3 respectively pass through the coil fixing part 1 and are connected to the current output device.

Specifically, the D-shaped coil 2 is arranged inside the O-shaped coil 3, and the D-shaped coil 2 is closely attached to the upper part of the O-shaped coil 3 at the position where it intersects with the O-shaped coil 3, and the intersecting area constitutes the target area 4. The current output device outputs a reference current for the D-shaped coil 2 to provide the reference magnetic field distribution strength and direction; the current output device provides an adjustment current for the O-shaped coil 3 to adjust the overall magnetic field distribution strength and direction of the DO double-circuit coil.

The DO double-circuit coil is provided with a target indicator 5 for determining the stimulation point in the target area 4, and an observation hole is arranged on the target indicator 5.

The D-shaped coil 2 is located on the upper layer and mainly plays a supporting role and provides reference stimulation. In the non-target target area, the distance between the lines is relatively large and mainly plays a supporting role. It can disperse the weight of the coil and the helmet so that the patient's head contacts the part No discomfort. In the target area, the line-to-line spacing is small, so that the magnetic field lines are focused on the target area and the impact on the non-target area is reduced; the dense wires in the target area give the target area a basic intensity and direction of the magnetic field distribution.

The O-shaped coil 3 is located in the lower layer, and mainly plays the role of adjusting the magnetic induction intensity and direction. On the basis of the basic magnetic field distribution provided by the D-shaped coil 2, by changing the direction and current intensity of the O-shaped coil 3, the DO double-circuit coil can be integrated. The strength and direction of the magnetic field distribution are adjusted to meet the expected design.

Both the D-shaped coil 2 and the O-shaped coil 3 are formed by multiple wires arranged in parallel; the distance between the multiple wires of the D-shaped coil 2 in the target area 4 is less than 3 mm, and the distance between the wires in the non-target area is greater than 10 mm. The multiple wires of the O-shaped coil 3 are closely attached to each other at various positions, and the distance between adjacent ones is less than 3mm. In this embodiment, the size of the target area 4 is approximately 3.5cm×3.5cm, with an area of about 12.25cm2.

As shown in FIG. 3 , a magnetic stimulation helmet includes a helmet body 6 and a transcranial magnetic stimulation coil disposed inside the helmet body 6 . Among them, the D-shaped coil 2 is close to the inner wall surface of the helmet body 6, and is used to closely fit the head during use; the O-shaped coil 3 is only close to the inner wall surface of the helmet body 6 in the target area 4, and other areas are away from the inner wall surface of the helmet body 6 .

The helmet body 6 is provided with an observation window 7, and the observation window 7 is directly opposite to the observation hole of the target indicator 5 on the target area 4. The doctor can observe the corresponding relationship between the target indicator 5 on the coil and the marking points on the supporting positioning cap of the present invention through the observation window 7, so as to intuitively consider the relative relationship between the internal stimulating coil and the patient's head during use. In order to roughly grasp the relative relationship between the stimulating magnetic field and the patient's brain target area during treatment. It can be observed whether the coil is out of the expected position and corrected during the long-term treatment process.

The magnetic stimulation helmet of the present invention is mainly divided into three parts, ①, the connecting part, which is mechanically connected with the host and the transcranial magnetic stimulation coil, so that it can produce the expected effective displacement in a limited extent and the helmet and the coil are relatively The location remains largely unchanged. ②. Circuit part. This part connects the air duct of the cooling system and the power supply circuit that generates magnetic pulses to the helmet, and collects temperature feedback signals in real time to ensure that the coil continues to work at a suitable temperature. ③. Treatment part. The function of this part is to ensure that the coil and the target area of the subject can fit as closely as possible during use and treatment. It mainly includes a shell design that is as light and fit as possible, and a transparent observation window design for the coil of the present invention at a special point. In addition, it also includes auxiliary parts, which are mainly auxiliary structures designed to ensure the normal use of

parts

①, ②, and ③. The design of straps and straps used to generate relative displacement, the structure of sponge pads and plastic templates for coils, and the design of communication cables for real-time monitoring.

The coil of the present invention adjusts the coil direction and structure so that during the treatment process, the comprehensive center of gravity of the coil of the present invention and the matching helmet and the center of gravity of the human body are roughly kept on the same axis, so as to reduce the coil tension caused by the pulling of the coil by gravity. The spatial deviation caused by the focused magnetic field and the intracranial target area of the patient improves the therapeutic effect in actual use.

The magnetic stimulation helmet of the present invention needs to be used with a positioning cap during the treatment process. In order to solve the problem that complex coils cannot be accurately positioned and reused during the treatment process, the coil matching positioning cap of the present invention adopts specific materials and designs on the premise of passing the biocompatibility test, and cooperates with the coil supporting treatment method of the present invention. The target focus point of the coil of the present invention can be fitted as close as possible to the target area of the patient's head during use, thereby increasing product safety and reliability.

The specific steps of use are as follows: the user chooses a suitable model among the three models of large, medium and small, and assists the patient to correctly wear the supporting positioning cap of the present invention, and the requirements are as follows:

1. The brim of the front hat is flush with the brow bone of the subject and perpendicular to the bridge of the patient's nose.

2. Keep the auxiliary line in the center of the positioning cap vertical and in line with the patient's nasal bridge, and pass through the patient's occipital prominence.

3. Flatten the top and position the hat surface so that it can be opened as much as possible without wrinkles.

4. Pull down the bands at both ends of the positioning cap and stick them on, making it suitable for wrapping the patient's jaw. Pull off the strap at the rear end of the positioning cap and stick it on so that it fits around the back of the subject's head.

During the repeated treatment of the patient with the positioning cap, it is necessary to ensure that the patient wears the same positioning cap, and the wearing requirements must be met to ensure that the relative position between the positioning cap and the patient's head remains unchanged.

A scale is printed on the left side of the front brim of the positioning cap, and a compass is printed on the top of the positioning cap to mark the recommended points for threshold stimulation. It must be used in conjunction with the coil and the helmet.

During the manufacturing process of the transcranial magnetic stimulation coil of the present invention, a magnetic induction intensity test is required, so as to fine-tune the structure of the magnetic stimulation coil. The coil magnetic induction test model adopted in the present invention includes a human skull model cut into three pieces. The thickness of the three skull models is 2mm, 13mm, and 18mm, and their corresponding anatomical positions are 1, hair and scalp respectively. The physiological significance of the available data of this skull model is the magnitude and distribution of the magnetic induction intensity on the scalp surface of the subject. ;2. The surface of the cerebral cortex. The physiological significance of the data available from this head model is the magnitude and distribution of the magnetic induction intensity received by the subject's cerebral cortex. 3. The surface cortex of the skull. The physiological significance of the data available from this head model is It shows the magnitude and distribution of the magnetic induction intensity that some specific tissues of the cranial cortex can receive.

Each layer of this model has a test point every 1mm on the coordinate axis of the horizontal plane projection, which is used for magnetic induction test positioning and repeated testing. The test points are centrally symmetrical, and each layer of test points can be one-to-one correspondence, which is used to study the different effects of the magnetic induction stimulation generated by the coil on the same point in the vertical tangential direction at different depths.

The specific test process is as follows:

Simulating the treatment process, the transcranial magnetic stimulation coil of the present invention is closely connected with the magnetic induction intensity test model of the coil of the present invention, and a semi-permanent fixation method is adopted to ensure the accuracy and repeatability of the test results. During the test, adjust the software of the host computer supporting the coil of the present invention to the single pulse mode, and the recommended output intensity is 65%. Before that, the three-phase Hall effect probe needs to be close to the mark point on the model, so that the front end of the probe is tangent to the inner surface of the model. Keep it as stable as possible, and read the original magnetic induction waveform on the oscilloscope connected to the magnetic induction testing instrument after the coil outputs the pulse. Since the magnetic field pulse of this coil is within 300μs, it is impossible to use the software algorithm that comes with the test instrument for direct reading. It can only record the original real magnetic induction intensity waveform, and after calculation, it is obtained when the intensity is 65%. The test points get the magnetic induction value. By repeating more than 500 points on the three models in this way, the magnetic induction intensity and distribution results with physiological significance can be obtained. The test data are shown in Figures 4 to 6.

In the figure, the rectangular frame abcd represents the focused area, and the rectangular frame a'b'c'd' represents the non-focused area, and the depth of the color corresponds to the magnitude of the magnetic induction. It can be seen from Figures 4 to 6 that the average magnetic induction intensity of the coil in the expected treatment target area can reach more than 85% of the strongest magnetic induction intensity at this depth, and the average magnetic induction intensity in the dangerous area that is expected to be avoided is limited to the maximum at this depth. Below 30% of the strong magnetic induction intensity is far from reaching the threshold of causing nerve depolarization, so it is safe. In summary, the coil has a wide focus area and the rules are easy to control, and it does not pose a safety risk to the dangerous area that needs to be avoided.

The following is an introduction to the entire positioning and treatment process, including the following steps:

1. The therapist helps the patient to correctly wear the positioning cap matched with this coil to ensure that the front brim of the cap coincides with the patient's brow bone, and the auxiliary treatment line in the middle of the positioning cap is on the same line as the bridge of the nose, so as to ensure that the treatment landmarks are worn repeatedly The position relative to the patient remains basically unchanged.

2. After the therapist measures the patient's head circumference, input the three sets of data into the medical instrument software used in conjunction with the coil to obtain the F3 point data, and use the scale matched with the coil to draw the mark points on the positioning cap.

3. Place the magnetic stimulation helmet of the present invention on the patient's head, move the helmet so that the target indicator on the coil coincides with the threshold reference point on the positioning cap, and on this basis, adjust the output power of the supporting medical instrument of the coil. During the process of stimulating the patient with a single pulse, observe the output of the matching electromyography tester, and move the helmet slightly, and find the minimum output power MT value that can stimulate the patient's thumb movement during this process.

4. Through the observation window 7 on the magnetic stimulation helmet, observe the corresponding relationship between the target indicator 5 on the coil and the marking points on the positioning cap, so that the target indicator 5 coincides with the marking points.

5. Ensure that the helmet logo is parallel to the central auxiliary treatment line of the positioning cap, fix the helmet strap with the patient's jaw, tighten the limit drawstring at the rear of the helmet, and use the medical equipment matched with this coil to output magnetic field pulses for treatment.

The embodiments described above have described the technical solutions and beneficial effects of the present invention in detail. It should be understood that the above descriptions are only specific embodiments of the present invention, and are not intended to limit the present invention. All within the scope of the principles of the present invention Any modifications, supplements and equivalent replacements should be included within the protection scope of the present invention.

Claims

A transcranial magnetic stimulation coil for deep precise magnetic stimulation, characterized in that it includes a coil fixing part and a DO double-circuit coil fixed by the coil fixing part, and the DO double-circuit coil includes an asymmetrically arranged D-shaped A coil and an O-shaped coil, the two ends of the D-shaped coil and the two ends of the O-shaped coil are connected to the current output device after passing through the coil fixing member;

The D-shaped coil is arranged inside the O-shaped coil, and the D-shaped coil is close to the upper part of the O-shaped coil at the position where it intersects with the O-shaped coil, and the intersecting area constitutes the target target area;

The current output device outputs a reference current for the D-shaped coil to provide the reference magnetic field distribution strength and direction; the current output device provides an adjustment current for the O-shaped coil to adjust the overall magnetic field distribution strength and direction of the DO dual-circuit coil.
The transcranial magnetic stimulation coil for deep precise magnetic stimulation according to claim 1, characterized in that, the DO double-circuit coil is provided with a target indicator for determining the stimulation point in the target target area, and the There is an observation hole on the target indicator.
The transcranial magnetic stimulation coil for deep precise magnetic stimulation according to claim 1, characterized in that, both the D-shaped coil and the O-shaped coil are formed by a plurality of wires arranged in parallel; The distance between the two wires in the target area is less than 3mm, and the distance between the two wires in the non-target area is greater than 10mm;

The multiple wires of the O-shaped coil are closely attached to each other, and the adjacent distance is less than 3mm.
The transcranial magnetic stimulation coil for deep precise magnetic stimulation according to claim 1, characterized in that the area of the target area is 10-13 cm2.
The transcranial magnetic stimulation coil for deep precise magnetic stimulation according to claim 1, characterized in that the magnetic induction intensity test of the transcranial magnetic stimulation coil needs to be carried out during the production process, comprising the following steps:

(1) Make a human skull model cut into three pieces, the corresponding anatomical positions of each piece are the hair and scalp, the surface of the cerebral cortex, and the superficial cortex of the skull;

(2) Set a test point every 1mm on the projection coordinate axis of the horizontal plane for magnetic induction intensity test positioning and repeated testing. The test points are in a state of central symmetry, and each test point can be one-to-one correspondence;

(3) Simulate the treatment process so that the coil of the present invention is closely joined with the human skull model made in step (1);

(4) Put the three-phase Hall effect probe close to the mark point to be stimulated on the human skull model, control the current output device to output pulses to the DO dual-circuit coil, and read the original magnetic induction through an oscilloscope connected to the three-phase Hall effect probe Intensity waveform, the magnetic induction intensity value of the test point is obtained after calculation;

(5) Using the method of step (4), the three-phase Hall effect probe is successively brought close to each test point on the human skull model to obtain the magnetic induction value of each test point;

(6) Draw the magnetic induction distribution map according to the magnetic induction intensity values of all test points, and fine-tune the shape of the transcranial magnetic stimulation coil according to the output pulse intensity and the magnetic induction distribution map.
The transcranial magnetic stimulation coil for deep precise magnetic stimulation according to claim 5, characterized in that in step (1), the thicknesses of the human skull models cut into three pieces are 2mm, 13mm and 18mm respectively.
A magnetic stimulation helmet, characterized in that it comprises a helmet body and the transcranial magnetic stimulation coil according to any one of claims 1 to 6; the transcranial magnetic stimulation coil is arranged inside the helmet body;

Wherein, the D-shaped coil is close to the inner wall surface of the helmet body, and is used to closely fit the head during use; the O-shaped coil is only close to the inner wall surface of the helmet body in the target area, and other areas They are all away from the inner wall surface of the helmet body; the current output device is arranged on the helmet body and connected with the supporting host.
The magnetic stimulation helmet according to claim 7, wherein the helmet body is provided with an observation window, and the observation window is directly opposite to the observation hole of the target indicator on the target area.