A kind of local enhancement type 8-shaped cerebral magnetic stimulation coilTechnical field
The invention belongs to transcranial magnetic stimulation technical field, in particular to a kind of local enhancement type 8-shaped transcranial magnetic stimulation lineCircle.
Background technique
Transcranial magnetic stimulation (Transcranial magnetic stimulation, abbreviation TMS) technology is a kind of using arteries and veinsMagnetic fields are rushed in central nervous system, changes the film potential of cortical neural cell, is allowed to generate induced current, influence intracerebral generationIt thanks and neural electrical activity, so as to cause a series of Neural stem cell technology of biochemical reactions.TMS has noninvasive, painless, safeFeature can be used for stimulating cranial nerve, nerve root and peripheral nerve.Be now widely used in Neuscience, brain science research field andThe diagnosing and treating of clinical disease.
Transcranial magnetic stimulation system consists of two parts: high pressure pulse generating system and stimulating coil.Existing stimulating coil masterTo be figure-eight coil, in order to accurately and effectively stimulate appointed part, to the magnetic field strength of coil generation, stimulation depth and gatherFocal power is proposed very high requirement.The degree of focus of Neural stem cell determines the stimulation selective power of magnetic stimulation system.High degree of focusField stimulation can be reduced, the possibility that unrelated nerve fiber is stimulated is reduced.Stimulation depth determines that magnetic stimulation system canKeep the distance of certain stimulus intensity.Need bigger stimulation deep if carrying out effective stimulus to intracranial deep nerve fiberDegree and higher degree of focus, however existing general figure-eight coil uses the plane coiling of uniform thickness wire rod, and depth and degree of focus is stimulated to haveThe problems such as limit, causes field stimulation big, and target spot selectivity is not strong.
Summary of the invention
The purpose of the present invention is to provide a kind of figure-eight coils with higher degree of focus, promote transcranial magnetic stimulation systemEffect of stimulation, to solve the problems, such as that existing uniform thickness figure-eight coil degree of focus is insufficient.
To achieve the above object, the present invention adopts the following technical scheme:
The thicker figure-eight coils such as general, in coil back center region processing at sunk area, so that hub of a spool position hasThickness d 1 is imitated, peripheral region keeps original thickness d2, d1 < d2.
A further improvement of the present invention lies in that: d1:d2=(0.2~0.8).
A further improvement of the present invention lies in that: sunk area is to be with two circular coil intersection points of the figure-eight coilCenter, radius are not more than the exradius of any one of circular coil.
A further improvement of the present invention lies in that: sunk area is located at the back side of the figure-eight coil, separate and patient contactDirection；The surface of two circular coils in front of the figure-eight coil is generally aligned in the same plane.
Compared with prior art, the invention has the following advantages that the present invention provides a kind of local enhancement type figure-eight coil,By the way that thicker figure-eight coil will be waited, in coil back center region processing at sunk area so that central area coil current fromStimulated zone is closer, so that pulsed magnetic field more stronger than uniform thickness structure is generated in the central area range, so that the partEnhanced figure-eight coil degree of focus is more preferable.
Detailed description of the invention
Fig. 1 is a kind of transcranial magnetic stimulation systematic schematic diagram；
Fig. 2 is existing figure-eight coil structural schematic diagram；
Fig. 3 is enhanced figure-eight coil schematic diagram of the present invention；
Fig. 4 is enhanced figure-eight coil different piece of the present invention in target point function and effect schematic diagram.
Specific embodiment
Below with reference to specification embodiment and Figure of description, invention is further explained.
A kind of transcranial magnetic stimulation systematic schematic diagram is provided herein, as shown in Figure 1, transcranial magnetic stimulation system generally passes through power supplyIt stores energy in energy storage pulsed capacitance, energy storage pulsed capacitance is then allowed to discharge stimulating coil rapid large-current, generate winkBetween pulsed magnetic field, patient is stimulated, general stimulating coil mostly uses figure-eight coil.
It please refers to shown in Fig. 2, existing figure-eight coil is uniform thickness structure, is made of two circular coils, and electric current is flowed from anodeEnter, by two circular coils, current direction is identical in two circular coil point of intersection, coil, coil is flowed out using cathode point,To obtain certain focusing magnetic field effect in two circular coil intersection areas.
Local enhancement type figure-eight coil proposed by the invention, by the way that thicker figure-eight coil will be waited, in the coil back sideLocal dent region is processed into heart district domain, so that the electric current by hub of a spool region is closer from stimulation point equivalent distances, thusPulsed magnetic field local enhancement effect is generated, it is more preferable to show as coil degree of focus.It please refers to shown in Fig. 3, in hub of a spool part 11,Coil thickness is d1；In peripheral part 12, coil thickness d2.General d2 is about 20mm, d1 10mm, by current elements position etc.Effect is that current carrying conductor center is estimated, then is equivalent in hub of a spool region, coil current when uniform thickness structure than being equivalent to from targetPoint wants nearly 5mm, and at coil surface 10mm, central area coil current is about with target point equivalent distances when uniform thickness structure coilCentral area coil current and target point equivalent distances will reduce 5mm when 20mm, d1 take 10mm, become 15mm.Sunk area modelIt encloses for centered on two circular coil intersection points, radius is less than the circular coil exradius, for example, circular coil exradiusFor 60mm, circular coil inner circle radius is 30mm, and sunk area radius is 30mm, then sunk area occupied area is total less than coilThe 15% of area ensure that the sunk area range interior loop current direction is identical, to the local enhancement type figure-eight coilThe electrical parameters such as inductance, D.C. resistance and heat-sinking capability influence very little, to the local enhancement type figure-eight coil in depressed areaRegional magnetic field distribution has little effect other than the corresponding central area spatial dimension in domain.The local enhancement type figure-eight coilIt is mainly characterized in that: under the conditions of same current in the magnetic field that space generates, in the corresponding central area spatial dimension of sunk areaInside there is local enhancement effect；Other than the corresponding central area spatial dimension of sunk area regional magnetic field distribution almost with etc. thickerFigure-eight coil is identical in the magnetic field that corresponding area of space generates.
It please refers to shown in Fig. 4, local enhancement type figure-eight coil of the present invention can be divided into two parts: being located in coilCentral part 11 of the heart district domain with a thickness of d1 and the peripheral part 12 with a thickness of d2.Target point P is in hub of a spool range line circleSurface distance is d, then is B11 as the magnetic field caused by target point P of central part 11, peripheral part 12 is produced in target point PRaw magnetic field is that B12, B11 and B12 are contrary, since 11 distance objective point P of central part is than 12 distance objective of peripheral partPoint P wants small, therefore the total magnetic field direction of B11 > B12, P point is consistent with B11, and size is (B11-B12).Take d1=10mm, d2=20mm, d=10mm, by current elements position be equivalent to current carrying conductor center estimation, then central part 11 to target point P it is equivalent away fromFrom for 15mm, and the equivalent distances of the 8 font identical central region of thicker such as corresponding and target point P are about 20mm, by electromagnetismKnowledge, the magnetic field approximation for having limit for length's conducting wire to generate and distance square are inversely proportional, i.e., under same current, enhanced figure-eight coilCentral part 11 generated at coil surface 10mm magnetic field about etc. thicker figure-eight coil same area coil in coil surface1.7 times of magnetic field are generated at 10mm, and magnetic field is mainly determined by electric current in the coil of central area at 10mm, farther out due to distance,Smaller by the other region coil influences in periphery, then the magnetic field at target point P is mainly B11.And at the corresponding center of sunk areaOther than regional space range regional magnetic field distribution almost with etc. the magnetic field phase that is generated in corresponding area of space of thicker figure-eight coilTogether, it is seen that enhanced figure-eight coil provided by the present invention is compared to the thicker figure-eight coil such as existing under same currentIt can be generated in a certain range of hub of a spool region and significantly increase effect, coil degree of focus be improved, more effectively to target pointRegion is precisely stimulated.
The above is only the preferred embodiments of the disclosure, but scope of protection of the present invention is not limited thereto, anyThose familiar with the art in the technical scope disclosed by the present invention, it is contemplated that change or replacement should all cover thisWithin the protection scope of invention.