JP5893689B2 - Continuous magnetic pulse generator - Google Patents

Description

  The present invention is an apparatus for enhancing the magnetic stimulation effect by using a coil having a magnetic core and a cooling mechanism when magnetically repetitively stimulating peripheral nerves or cerebral cortical motor areas in order to enhance the motor function of the extremities. About.

  Currently, there are 2 million patients with hemiplegia due to stroke and limb paralysis due to spinal cord injury, and the number is further increasing due to the transition of Japanese age structure. When limb paralysis continues for a long time due to brain damage, the disuse syndrome significantly reduces muscle function and makes recovery difficult. Rehabilitation by exercise therapy is the most important treatment method to prevent disuse syndrome due to hemiplegia and quadriplegia and to actively restore muscle function.

  “Brain machine interface (AMI)” technology, which detects brain waves and uses them as trigger signals to move paralyzed limbs by electrical stimulation, is attracting attention. Although application to rehabilitation has been attempted, there is a technical limitation that the target electroencephalogram cannot be detected when the cortical motor area is functionally impaired. If the paralyzed limb is not moved, it becomes a disuse syndrome and it becomes difficult to recover the motor function. Therefore, rehabilitation for assisting exercise with assistance or equipment is widely performed. On the other hand, it is not easy to voluntarily exercise a paralyzed limb due to cerebral dysfunction, but it can be moved by external physical stimulation if there is no abnormality in nerves or muscles.

  Methods have been developed to induce muscle movement by electrically stimulating peripheral nerves and cortical motor areas. As an electrical method, transcutaneous electrical nerve stimulation TENS is widely used. This principle is to restore motor function by moving limbs by electrically stimulating motor nerves from the outside. In order to obtain large muscle contraction by electrical stimulation, strong electrical stimulation is required. Since this phenomenon is the same as electric shock, it is accompanied by discomfort and pain due to electric shock. Various studies have been conducted, such as improving the frequency and waveform in order to reduce shock, but the problem of significant increase in pain is unavoidable when large muscle contraction is exceeded by electrical stimulation.

  Pain associated with electrical stimulation is perceived by pain nerves distributed near the surface of the skin. Therefore, the pain of electrical stimulation can be relieved by implanting the stimulation electrode under the skin. However, since it is necessary to always leave the signal line outside the body, the embedded electrode has a big problem of bacterial infection from the wound.

  Another method for electromagnetically stimulating nerves without using contact electrodes is magnetic stimulation. This is a method in which a pulse current is passed through a coil placed near a nerve, and the muscle is moved by stimulating the nerve with an induced current generated in the nerve. This magnetic stimulation method does not require a process such as attaching or embedding electrodes, and in addition, there is almost no electric shock or pain caused by electric shock. For this reason, there is an advantage that strong stimulation is possible as compared with the electrical stimulation method and a large muscle contraction can be obtained. For this reason, electrical stimulation is being applied to diagnosis and treatment of diseases, and has been put to practical use as Transcranial Magnetic Stimulation (TMS: Trans-cranial Magnetic Stimulation). In particular, the combination of rTMS that repeats magnetic stimulation and exercise therapy has a large rehabilitation effect (Non-patent Documents 1 and 2).

  Muscle contraction caused by electrical and magnetic stimulation includes (1) muscle contraction and single contraction, and repeated muscle contraction in which the movement continues, (2) continuous muscle contraction in which fingers are bent or limbs move greatly, It is divided into two types. As a device that repeatedly causes muscle contraction (1), there is a high-frequency electrical stimulation device for the purpose of stiff shoulder treatment. The muscle contraction caused by this device is a periodic vibration of the muscle at the target site.

  As an invention that utilizes the muscle contraction effect by magnetic stimulation, there is a urinary incontinence treatment device of Patent Document 1. This device performs a urinary incontinence treatment by generating a pulsed magnetic field of 0.01 to 3 Tesla from 1 to 100 Hz from a magnetic stimulation coil fixed to a chair or body, and repeating periodic contraction of the bladder sphincter. Is.

  A technique for bending a finger or arm continuously by magnetic stimulation, instead of simple muscle contraction as in urinary incontinence treatment, is shown in Patent Document 2, and a nerve pulse is repeatedly magnetized at intervals of 10 milliseconds. Stimulation has been shown to increase the distance at which the arm bends as the number of pulses increases.

  The effect of magnetic stimulation increases with the number of repetitions of magnetic stimulation. However, in order to cause magnetic stimulation, it is necessary to pass a large current of several hundred amperes or more through the coil. For this reason, magnetic stimulation by continuous pulses has a problem that the number of pulses cannot be increased because the heat generation / temperature rise of the coil is severe. The heat generated by the coil is a major technical limitation for continuous magnetic stimulation.

  In order to reduce the heat generation of the magnetic stimulation coil, it is effective to use a coil with a magnetic core (magnetic core) that can obtain a strong magnetic field with a small current. For this reason, patent applications relating to magnetic stimulation coils with a magnetic core for transcranial magnetic stimulation have been filed. Patent Document 3 discloses a magnetic stimulation device that obtains a convergent magnetic field by cutting a part of an O-type magnetic core, thinning an opposing part, and winding a coil therearound.

  As an improved version of Patent Document 2, Patent Document 4 discloses a magnetic stimulation device in which a magnetic material is arranged in a space formed inside a winding. Patent Document 5 discloses a transcranial magnetic stimulation technique in which a coil is wound around a horseshoe-shaped magnetic core from a semi-circular circle having a high magnetic permeability to reduce the heat generation of the coil, thereby performing magnetic stimulation of the brain. Patent Document 6 discloses a technique of using a ferromagnetic material having a magnetic permeability and a high saturation magnetic flux density for a magnetic core having a shape similar to this.

  Since the exciting pulse current is high-frequency, only the coil surface flows, and there is a problem that even if a thick wire is used, the electric resistance increases. In order to prevent this, Patent Document 7 describes a technique for reducing heat generation of a coil by bundling thin litz wires, which are conventional means of a high-frequency coil, and winding the coil.

Ishiyaku Shuppan Co., Ltd. “Basics and Applications of Magnetic Stimulation” by Ide, Cerebrovascular Disorders, 198 Central Law Publishing Co., Ltd. “Recovering Body and Brain” by Ide, an example of paralysis improved by magnetic stimulation. 183

Japanese Patent Laid-Open No. 10-234870 JP 2010-166971 A JP-A-7-171220 JP-A-8-52231 JP 2000-504966 Gazette JP-T-2001-525947 JP 2002-306614 A

  According to continuous magnetic stimulation, a strong magnetic stimulation effect can be obtained, so that it is possible to induce a large movement of fingers and limb muscles. However, when the magnetic pulse is repeatedly generated, the coil generates heat due to Joule heat generated by the coil current. When a magnetic core having a high magnetic permeability is used to reduce the heat generation of the coil, the coil current for generating a magnetic field having the same strength is reduced, so that the heat generation of the coil is reduced. However, since the magnetic core generates heat due to the eddy current generated in the magnetic core, the coil including the magnetic core has a problem of heat generation as well as the air-core coil. An object of the present invention is to put to practical use a continuous magnetic pulse generator that allows a large number of continuous magnetic stimulations with little temperature rise due to heat generation.

The continuous magnetic pulse generator A according to claim 1 is a case where the gas 6 is used for cooling,
A T-shaped magnetic core 2 in which a large number of rolled silicon steel sheets are laminated;
A coiled conductor 1 wound around the leg 2a of the magnetic core 2 with a coil cooling gap 3 between them and wound a plurality of times;
A convex portion 4d having a coil cooling air hole 5, in which the magnetic core 2 and the coiled conductor 1 are housed, and a concave portion into which the leg portion 2a of the magnetic core 2 is fitted is formed. A casing 4 at the center of the lower surface;
A cooling gas 6 that flows through the coil cooling gap 3 is supplied to the casing 4 or a cooling mechanism 7 that discharges the cooling gas 6 from the casing 4.

  A second aspect of the present invention is the continuous magnetic pulse generator A according to the first aspect, wherein a core cooling gap 8 is provided between the magnetic core 2 and the casing 4.

  According to a third aspect of the present invention, in the continuous magnetic pulse generator A according to the second aspect of the present invention, the casing 4 is provided with a core cooling air hole 9 communicating with the core cooling gap 8.

The continuous magnetic pulse generator A according to claim 4 is a case where a liquid is used for cooling,
A T-shaped magnetic core 2 in which a large number of rolled silicon steel sheets are laminated;
A coiled conductor 1 wound around the leg 2a of the magnetic core 2 with a coil cooling gap 3 between them and wound a plurality of times;
A casing 4 in which the magnetic core 2 and the coiled conductor 1 are housed, and a convex portion 4d formed on the inner side with a concave portion into which the leg portion 2a of the magnetic core 2 is fitted;
The coil cooling gap 3 is provided with a cooling pipe 11 through which the cooling liquid 10 flows.

  According to a fifth aspect of the present invention, in the continuous magnetic pulse generator A according to the fourth aspect, a cooling pipe 11 is further wound around the magnetic core 2.

  A sixth aspect of the present invention is the continuous magnetic pulse generator A according to the fourth or fifth aspect, wherein a core cooling gap 8 is provided between the magnetic core 2 and the casing 4.

A seventh aspect is characterized in that, in the continuous magnetic pulse generator A according to the second or sixth aspect , a heat insulating material 12 is provided in the core cooling gap 8.

  In the continuous magnetic pulse generator A according to the present invention, first, a coiled conductor 1 having a coil cooling gap 3 is wound around a magnetic core 2 a plurality of times, and the coil cooling gap is wound around the coil core. 3 even when a large current is continuously flowed by flowing a gas 6 through 3 or by flowing a cooling liquid 10 through a cooling pipe 11 disposed in a coil cooling gap 3. The heat is taken away by the cooling gas 6 or the cooling liquid 10, and the temperature of the conductor 1 can be maintained at an appropriate temperature.

  Furthermore, by providing the core cooling gap 8 between the magnetic core 2 and the casing 4, the temperature rise of the magnetic core 2 can be suppressed. Further, if a core cooling vent hole 9 communicating with the core cooling gap 8 is provided in the casing 4, the gas 6 flows through the core cooling gap 8 through the core cooling vent hole 9, and the magnetic core. 2 can be simultaneously cooled. This is the same even when the cooling pipe 11 is further wound around the magnetic core 2. In other words, even when a portion where the magnetic flux is concentrated in the core housing portion of the continuous magnetic pulse generator A during treatment is brought into contact with the affected area, it can be suppressed to a temperature at which thermal damage such as burns does not occur. Furthermore, if the heat insulating material 12 is provided in the core cooling gap 8, even if the temperature of the magnetic core 2 rises to an appropriate temperature or higher, for example, about 80 ° C., it is blocked by the heat insulating material 12, Does not harm the patient.

By using such a continuous magnetic pulse generator A having the cooling mechanism 7, it is possible to continuously and greatly move muscles that are difficult to move spontaneously due to paralysis due to cerebral dysfunction or the like by the action of a pulsed magnetic field. become. The same muscle contraction effect can be achieved by electrical stimulation. However, electrical stimulation involves (1) discomfort and pain similar to electric shock, (2) it takes time to attach or embed electrodes, and (3) There is a risk of burns due to energization. However, magnetic stimulation does not have these problems (1) to (3). Even if limb paralysis occurs due to cerebral dysfunction, the nervous system and muscles are not damaged. Therefore, the motor function can be restored by appropriate rehabilitation treatment. However, if the state of consciousness or bedridden continues, motor function cannot be restored due to the disuse syndrome. If continuous magnetic stimulation is performed using the continuous magnetic pulse generator A having the cooling mechanism 7 according to the present invention, the paralyzed limbs and finger muscles can be effectively exercised, so that the rehabilitation effect is significantly improved. It is expected.

It is a perspective view of the present invention. It is a perspective view of the modification of the cooling mechanism of FIG. It is sectional drawing of FIG. It is a section perspective view of the modification of the core of the present invention. It is a section perspective view in case the cooling mechanism of the present invention is water cooling. It is a principal part cross-sectional perspective view of the further modification of the cooling mechanism of FIG.

  Next, details of the present invention will be described based on examples. This embodiment is intended to facilitate understanding by those skilled in the art. In other words, it should be understood that the present invention is limited only by the technical idea described in the entire specification of the present invention, and is not limited to the present embodiment.

  The continuous magnetic pulse generator A according to the present invention includes a T-type magnetic core 2 and a simple plate-type one, and there are air cooling and water cooling methods. First, the case where the magnetic core 2 is T-shaped and air-cooled will be described. The continuous magnetic pulse generator A includes a conductor 1, a magnetic core 2, a casing 4, and a cooling mechanism 7.

  The magnetic core 2 is formed by laminating a large number of rolled silicon steel sheets with thin insulating coatings. In the embodiment of FIGS. 1 and 2, a rolled silicon steel sheet is formed in a T shape and laminated. The rolled silicon steel sheet used in this example has a thickness of 0.35 mm.

  The conductor 1 is obtained by winding a long copper plate in a coil shape, and an insulating coating is formed on the surface thereof. In this embodiment, the conductor 1 has a thickness of 2 mm and a width of 13 mm. A coil cooling gap 3 is provided so as not to contact each other, and a long copper plate is wound in a coil shape. In this embodiment, the volume is 10 volumes. The coil cooling gap 3 is 1 mm in this embodiment. The insulating coating was made of urethane resin and thinned so as not to disturb the heat radiation on the surface of the conductor 1. In this example, the thickness of the insulating coating was 20 μm. In the present embodiment, the conductor 1 is formed by winding a long copper plate in a coil shape, but is not limited thereto, and may be any as long as the coil cooling gap 3 is provided. It may be formed by providing a gap 3 for use and winding a copper wire in a coil shape.

  The casing 4 is made of a resin (here, made of polyethylene) that houses the magnetic core 2 and the coiled conductor 1, and is formed by a main body 4 a having an upper surface opened and a lid portion 4 b covering the opening. It is fixed with a bolt (not shown), and the upper surface opening is closed. A handle 4c is provided on the upper surface of the lid 4b as necessary. A convex portion 4d bulging downward is formed at the center of the lower surface of the main body 4a that contacts the affected area of the patient. A large number of coil cooling vents 5 are formed around the convex portion 4d at positions corresponding to the coil cooling gaps 3 of the conductor 1 wound in a coil shape on the lower surface of the main body 4a. In the present embodiment, a large number of core cooling air holes 9 are also formed in the convex portion 4d.

  Since the cooling mechanism 7 is air-cooled in this embodiment, in the case of FIG. 1, the ventilation nozzle 7a provided on the side surface of the main body 4a or the fan 7b provided on the ventilation portion 7c on the side surface of the main body 4a shown in FIG. . The ventilation nozzle 7a is connected to an exhaust device (not shown), and the air in the casing 4 is sucked. (Alternatively, cooling air is blown into the casing 4 by the air supply device.) In the drawing, the ventilation nozzle 7a or the fan 7b is provided on the side surface of the casing 4, but it is not necessarily limited to this position.

  The conductor 1 wound in the coil shape is accommodated in the main body 4a, and the coil cooling gap 3 of the conductor 1 wound in the coil shape coincides with the coil cooling vent hole 5 of the main body 4a as described above. It arrange | positions and it fixes to the main body 4a by the fixing member (or adhesion | attachment) which is not shown in figure. On the other hand, the leg portion 2a of the T-shaped magnetic core 2 is inserted into the space portion of the central portion of the conductor 1 wound in a coil shape. The leg portion 2a is fitted into a concave portion inside the convex portion 4d of the main body 4a, and the conductor 1 wound in a coil shape is wound around the leg portion 2a in a spiral shape. And the lower end of the leg part 2a will be in the state which protruded slightly from the lower surface of the conductor 1 wound by the coil shape (in this embodiment, the protrusion amount is 3 mm). The lower end surface of the leg 2a is separated from the concave portion inside the convex portion 4d (this space portion becomes the core cooling gap 8). It is fixed by the method like.

  Next, use of the apparatus A will be described. When a pulse current is continuously applied to the coiled conductor 1 with the device A in contact with the skin surface of the patient's arm, a magnetic pulse is generated on the surface of the magnetic core 2 and the median nerve in the muscles. Stimulated. This caused the wrist to bend inwardly without causing pain. In addition, when the quadriceps muscles of the foot were stimulated, the foot was kicked forward at a walking speed. The energizing condition at this time is a peak current flowing through the coil of 1600 A, and a magnetic pulse with a biphasic waveform (one plus and one minus) with a pulse width of 0.2 milliseconds is generated at about 100 at 50 per second. I am letting. Of course, the energization condition is not limited to this, and an appropriate condition is selected for each patient. Further, although the efficiency is reduced, the waveform of the magnetic pulse may be monophasic (plus or minus one wave).

  During the energization, the cooling mechanism 7 continues to operate (that is, exhaust or supply air by the ventilation nozzle 7a or the fan 7b), and cooling air flows from the coil cooling vent hole 5, and the heat of the coiled conductor 1 is dissipated. Take away. This air also flows into the core cooling gap 8 between the magnetic core 2 and the casing 4 to cool the convex portions 4d and the leg portions 2a of the magnetic core 2.

  When a magnetic pulse is continuously generated for 1 minute at a room temperature of 25 ° C. (total number of pulses of 3000), the temperature at the center of the surface of the leg 2a of the magnetic core 2 is 45 ° C., which is a thermal risk to the patient. This cooling effect was sufficient.

  In addition, when the cooling mechanism 7 was stopped under the same conditions as described above (however, the energization time was continuous 500 shots in 10 seconds), the surface temperature exceeded 60 ° C., and there was a risk of burns.

  In addition, as described above, cooling air may flow through the core cooling gap 8 between the magnetic core 2 and the casing 4. However, in order to obtain a higher cooling effect, the core cooling is applied to the convex portion 4 d of the casing 4. A magnetic core cooling vent 9 communicating with the gap 8 may be provided so that cooling air can be taken into the core cooling gap 8 from the outside. Further, a heat insulating material 12 may be provided in the cooling gap 8 instead of the magnetic core cooling vent 9.

FIG. 4 shows another embodiment of the magnetic core 2. The magnetic core 2 is formed by laminating the above-described silicon steel plates in a square bar shape, and press-fitting the upper portion thereof into, for example, the through holes 13b of the cooling fins 13 made of aluminum. This is an example of mounting so that the shape is T-shaped. The cooling fins 13 are formed with a large number of cooling gaps 13a in the vertical direction, and heat is taken away when the air passes through the cooling gaps 13a, so that the temperature of the magnetic core 2 in contact with the cooling fins 13 is increased. Decreases. If the upper surface of the conductor 1 covered with the thin insulating film is brought into contact with the cooling fins 13, the heat of the conductor 1 moves from here to the cooling fins 13, and the cooling of the conductor 1 can be promoted. . In addition, although the appearance of a pulse does not change whether the magnetic body core 2 is I-shaped or T-shaped, the merit of making it T-shaped is as follows.
1 When the magnetic path area is the same, the surface area becomes large, so cooling is easy.
2 Since the height direction can be suppressed, the coil becomes compact.
3 Since the magnetic flux does not escape upward, a device that is vulnerable to an external magnetic field such as a fan can be disposed on the upper part of the coil.

  FIG. 5 shows a case of water cooling, in which a cooling pipe 11 is provided so as to contact the leg 2a of the magnetic core 2 and / or the coiled conductor 1 so that the cooling fluid flows. Thereby, the leg 2a and the conductor 1 are more effectively cooled.

  A: Continuous magnetic pulse generator, 1: conductor, 2: magnetic core, 2a: leg, 3: coil cooling gap, 4: casing, 4a: main body, 4b: lid, 4c: handle, 4d: convex , 5: coil cooling vent, 6: cooling gas, 7: cooling mechanism, 7a: nozzle, 7b: fan, 7c: vent, 8: core cooling gap, 9: core cooling vent, 10: Cooling liquid, 11: cooling pipe, 12: heat insulating material, 13: cooling fin, 13a: clearance for cooling, 13b: through hole.

Claims (7)

A T-shaped magnetic core in which a large number of rolled silicon steel sheets are laminated;
Around the leg of the magnetic core, a coiled conductor wound multiple times with a coil cooling gap between each other;
A casing having a coil cooling ventilation hole, in which the magnetic core and the coil-shaped conductor are housed, and a convex portion formed inside the concave portion into which the leg portion of the magnetic core is fitted is formed at the center of the lower surface thereof; ,
A continuous magnetic pulse generator comprising: a cooling mechanism for supplying or discharging cooling gas flowing through the coil cooling gap to the casing.   2. The continuous magnetic pulse generator according to claim 1, wherein a core cooling gap is provided between the magnetic core and the casing.   3. The continuous magnetic pulse generator according to claim 2, wherein the casing is provided with a core cooling air hole communicating with the core cooling gap. A T-shaped magnetic core in which a large number of rolled silicon steel sheets are laminated;
Around the leg of the magnetic core, a coiled conductor wound multiple times with a coil cooling gap between each other;
A casing having a convex portion formed in the inside of a concave portion in which the magnetic core and a coiled conductor are housed and into which a leg portion of the magnetic core is fitted;
A continuous magnetic pulse generator comprising a cooling pipe disposed in a coil cooling gap and through which a cooling liquid flows.   5. The continuous magnetic pulse generator according to claim 4, further comprising a cooling pipe wound around the magnetic core.   6. The continuous magnetic pulse generator according to claim 4, wherein a core cooling gap is provided between the magnetic core and the casing.   7. The continuous magnetic pulse generator according to claim 2, wherein a heat insulating material is provided in the core cooling gap.

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