CN100477026C - Superconductor magnet for magnetic surgical operation and coil winding method thereof - Google Patents
Superconductor magnet for magnetic surgical operation and coil winding method thereof Download PDFInfo
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- CN100477026C CN100477026C CNB2004100094857A CN200410009485A CN100477026C CN 100477026 C CN100477026 C CN 100477026C CN B2004100094857 A CNB2004100094857 A CN B2004100094857A CN 200410009485 A CN200410009485 A CN 200410009485A CN 100477026 C CN100477026 C CN 100477026C
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Abstract
A superconductive magnet being used for neurosurgery consists of three coils being prepared in small size, in medium size and big size separately in shape of hollow ball table. Three said coils are nested to each other and placed in orthogonal to each other as each ball table shaped coil occupies latitude angle range of 10 to 80 degree. A winding method of coil uses a half piece of wire to wind along axis of coil frame from small radius end D to big radius end C , then uses another half piece of wire to wind from counter direction .
Description
Technical field
The present invention relates to a kind of magnet and coil winding method thereof, particularly a kind of superconducting magnet and magnet coil winding method thereof that is used for neuro-surgery operation usefulness.
Background technology
In the insertion type operation of routine, surgical catheters is inserted in artery or the vein by human epidermal, the motion of conduit is to apply power by the rear end at conduit to realize, therefore conduit must be made by very hard material, to guarantee that conduit bending can not take place in the process that advances, but because conduit is harder, if institute is comparatively complicated through the path, conduit destination unreachable often then.Therefore in the significant points (as heart, brain) of some human body, conventional insertion type therapy has been full of challenge and complexity, usually needs to spend skilled doctor's long time.
What is called magnetic navigation stereotaxic surgery system refers under the effect of computer-controlled three-dimensional magnetic field, under the guiding of stereotactic system, imaging system, ferromagnetic substance path movement according to the rules in the feasible implant into body in advance, the method that directly acts on the affected part or guide various operation devices (as insertion type conduit, radioactive substance etc.) in human body, to carry out the operation of all kinds of complexity.This system uses the method that is different from existing neuro-surgery insertion type operation, utilize the interaction force guiding interposing catheter of ferromagnetic substance in external magnetic field that superconducting magnet produces and the operating theater instruments to finish complicated operation technique in patient's body, whole operation is finished in the supervision of CT imaging system and computer with under controlling.
The existing similarly device of the U.S. is used for clinical testing and research at present, in order to produce the ferromagnetic material that the guide catheter front end is come in suitable three-dimensional magnetic field in the operative space of a sphere.United States Patent (USP) 6,014,580 propose a kind of device: build the magnet system of being made up of the solenoid coil of three pairs of mutually orthogonal placements, promptly form by six coils that are symmetrically distributed in twos altogether, control the motion of ferromagnetic material by the size that changes electric current in the coil. by the Earnshaw theorem as can be known, in order to make ferromagnetic material stable controlled motion in magnetic field, need to introduce feedback control loop, just mean that also electric current needs in the coil constantly change and vibrate.
Because the gradient of the stressed and external magnetic field of ferromagnetic material in magnetic field is relevant with the magnetic dipole moment of ferromagnetic material itself, derivation result from formula, in the space, three-dimensional magnetic field that produces by three pairs of solenoid coils, corresponding relation between magnetic field gradient and the space coordinates point is very complicated, in order to make accurate control to the motion of surgical catheters, the position coordinates of each ferromagnetic material constantly that needing obtains to perform the operation accurately carries out, this has proposed very high requirement to supervisory control system.
Although solenoid coil has simple in structure as a kind of magnet coil structure of widespread usage, build easily, advantage such as easy to use, but magnetic field gradient Changing Pattern complexity is arranged also, magnetic field gradient is less, other shape coil is bigger relatively for inductance, being unsuitable for being applied in electric current variation occasion greatly. above-mentioned magnetic surgical system has proposed new requirement to magnet system, be that magnetic field gradient is relatively large, Changing Pattern is simple relatively, inductance is less relatively etc., adopts the magnet coil of said structure to fail to satisfy these requirements.
Summary of the invention
For overcoming the shortcoming of prior art, it is relatively large to satisfy magnetic field gradient, and Changing Pattern is simple relatively, the magnetic operation requirement that inductance is less relatively, the present invention proposes a kind of superconducting magnet that adopts the new coil structure, it mainly comprises superconducting coil, cooled cryostat and screen.Superconducting coil by large, medium and small three together mutually nested, and the hollow billiard table shape coil of mutually orthogonal placement forms, the axis of three coils is respectively the x of rectangular coordinate system, y, the z axis, the axes intersect of three coils is in a bit.For the ease of mutually nested, the endosphere radius of the hollow billiard table shape coil during the outer radius of sphere of little hollow billiard table shape coil is slightly less than, in the outer radius of sphere of hollow billiard table shape coil be slightly less than the endosphere radius of big hollow billiard table shape coil, the radius of each hollow billiard table shape coil and thickness need the size of the magnetic field gradient that produces to decide by them separately.Large, medium and small three mutually nested hollow billiard table shape coils constitute 7/8 spherical magnet.Whole magnet places one 7/8 spherical cooled cryostat, cooled cryostat outer wrapping screen.
Each hollow billiard table shape coil is made up of two symmetrical eccentric circular rings along the cross section of axis, the folded angle of latitude in eccentric circular ring two sides is to spend to 80 degree from 10, be that the occupied angle of latitude scope of eccentric circular ring is less than 70 degree, two occupied angle of latitude scope sums of eccentric circular ring are called angle of strike, and the angle of strike of each billiard table shape coil is all less than 140 degree.
The present invention is continuous coiling on the spherical shell surface of billiard table shape coil rack, change the spatial distribution in magnetic field by each circle coil radius in each layer along the continuous variation of sphere, in the space of spherical shell inner chamber, produce a uniform gradient magnetic vertically and radially.Because the working region of this operation device is a linear medium, magnetic field meets superposition theorem, the uniform gradient magnetic field stack of the hollow billiard table shape coil of placing by three quadratures can produce the equally distributed gradient magnetic of any size and Orientation in the spherical shell intracavity space.
Magnet coil of the present invention in same layer line circle each circle coil diameter variation vertically as the variation of spherical curve, and again by aforesaid specific region coiling on round platform, can eliminate other multipole magnetic field components, so can produce a higher uniform gradient magnetic field. therefore can obtain the gradient magnetic big than the equal diameter magnetic plug.
Because it is much smaller that the volume of the hollow billiard table shape coil among the present invention produces the solenoid of onesize gradient magnetic relatively, so the inductance of coil is also less among the present invention, and the also relative solenoid of stray field is little.In summary, hollow billiard table shape coil of the present invention is compared with the solenoid coil of same volume has the magnetic field gradient height, the magnetic field size is simple with space coordinates change in location rule, advantages such as the while inductance is less relatively again, in addition, compare with the plain solenoid coil, hollow billiard table shape coil has smaller volume, and its shape is very suitable for the usefulness of cerebral surgery operation.Therefore this structure can enlarge range of operation, and the operation of being convenient to perform the operation has improved the performance of system.
In order to make the hollow billiard table shape of superconduction coil working in the environment of low temperature, cooled cryostat of the present invention is one 7/8 spherical Dewars, the outer radius of this sphere Dewar is a bit larger tham the outer radius of maximum empty bulbus cordis platform shape coil in three coils, inside radius is slightly less than the inside radius of minimum hollow billiard table shape coil, so that whole winding is wrapped up, for it provides cooler environment.
Magnet of the present invention also comprises the screen in the magnet system except the hollow billiard table shape coil that comprises above-mentioned generation uniform gradient magnetic field.Screen is arranged in the outer room temperature region of spherical Dewar.This screen is 7/8 shielding spherical shell, the employing soft ferromagnetic material is made, and its inside radius is slightly larger than the outer radius of spherical Dewar, so that whole Dewar is wrapped up, to reduce the magnetic field influence in inoperative zone to external world, the Distribution of Magnetic Field to the working region does not influence simultaneously.Shell thickness is by the magnetic field size decision of required shielding.Whole like this magnet structure is followed successively by spherical coil, cooled cryostat, screen from inside to outside.
The processing step of superconducting coil winding method of the present invention is:
At first make hollow billiard table shape coil rack.Skeleton adopts hollow billiard table of stainless steel and stainless steel long radius end plate and the welding of minor radius end plate to make.On the long radius end plate, need to beat some holes in advance, prepared against the usefulness of line, joint.Before coiling, also need to determine the required class of insulation, select the appropriate insulation lacquer evenly to be applied on the skeleton according to the operating voltage of coil.Then according to winding the line from the direction of minor radius end plate to the long radius end plate, adopt the method for winding of " double-cake coils ", in the middle of a lead, earlier at the middle part of minor radius end plate with the clamping apparatus static line, pasting the spherical shell face with its half root lead, around the axis of hollow billiard table shape coil rack from the minor radius end plate to long radius end plate one coiling of enclosing the land, treat this half root wire-wound intact after again from the minor radius end plate to the long radius end plate around other half root lead, but its direction of winding is opposite with preceding half root direction of winding.And select suitable layer insulation and turn-to-turn insulation according to the electric pressure of coil, generally for superconducting line, because the working voltage of coil is very low, and superconducting line itself also has enough insulation levels, therefore do not need generally to consider whether turn-to-turn insulation and layer insulation, the interlayer of coil need packing material then to depend on the running current of coil and the factor of heat radiation.Suffered electromagnetic stress is selected suitable stress safeguard procedures when moving according to coil after coil winding is finished again, and generally adopts epoxy resin cure and adds method such as stainless steel band colligation.At last the coil that winds is placed a hemispherical shell, finish the coiling work of a hollow billiard table shape coil.The winding method of two other hollow billiard table shape coil is the same, and after treating three coils all coiling being finished, whole spherical magnet coil is finished in assembling at last.
Description of drawings
Fig. 1 a is the hollow billiard table shape of a magnet of the present invention coil embodiment schematic diagram, and Fig. 1 b is a magnetic surgical system work schematic diagram; Among the figure: 1,2,3 is hollow billiard table shape coil, the working region of 4 magnetic surgical systems, 9 cooled cryostats, 10 screens.
Fig. 2 is the front view of the hollow billiard table shape of magnet of the present invention coil embodiment;
Fig. 3 a is single hollow billiard table shape coil vertical view; Fig. 3 b is a single hollow billiard table shape coil profile (along the section of A-A among the accompanying drawing 3a); Among the figure: the left-half of coil in 5 profiles; The right half part of coil in 6 profiles; The symmetry axis of 7 coils; The minor radius end face of the right half part of B coil; The long radius end face of the right half part of A coil;
Fig. 4 a is a single hollow billiard table shape coil rack profile (along the section of the A-A among the accompanying drawing 3a); Fig. 4 b is the coil winding method schematic diagram; Among the figure: 8 hollow billiard table shape stainless steel insert spherical shells; D minor radius end plate; C long radius end plate;
Embodiment
The present invention is further described below in conjunction with drawings and Examples.
Shown in Fig. 1 a and Fig. 1 b, the different hollow billiard table shape coil 1,2,3 of radius that the hollow billiard table shape of magnet of the present invention coil is placed by large, medium and small three quadratures is formed.The axis of three coils is respectively the x of rectangular coordinate system, y, and the z axis, and intersect at a point.For the ease of mutually nested, the endosphere radius of the hollow billiard table shape coil 1 during the outer radius of sphere of little hollow billiard table shape coil 2 is slightly less than, in the outer radius of sphere of hollow billiard table shape coil 1 be slightly less than the endosphere radius of big hollow billiard table shape coil 3.Dash area 4 among Fig. 1 b is represented the working region of magnetic surgical system, for example patient's head can be placed this zone, finishes corresponding neuro-surgery operation.Three mutually nested hollow billiard table shape coils 1,2,3 constitute 7/8 spherical magnet, and whole spherical magnet places a cooled cryostat 9, cooled cryostat 9 outer wrapping screens 10.
Fig. 2 is the vertical view of the hollow billiard table shape of magnet of the present invention coil, comprises three hollow billiard table shape loop constructions 1,2,3.All have circular hole in each hollow billiard table shape coil top, it not only can deep and remotely cover sense for what imaging system provided watch window but also can remove the patient, eliminates patient's frightened mood, helps the patient and keeps good psychological condition.On theoretical analysis and calculation, in order to produce needed uniform gradient magnetic field, the current density in the coil should (2 * Φ) rule distributes, and J represents current density, and I represents the base value of electric current according to J=I * sin along the spherical shell surface.Φ representative angle along the circumferential direction.Continuously change current density in the magnet coil and need continuously change the activity coefficient of coil, this is difficult the realization on engineering, therefore, according to analyzing and calculating, it is the hollow billiard table shape coil of 15 degree and 75 degree (being that whole billiard table angle of strike is 120 degree) that present embodiment adopts the angle of latitude of eccentric circular ring two sides, the current density of coil remains steady state value in this angular range, so both be convenient to the construction of coil, can produce required magnetic field space again and distribute.Simultaneously this hollow billiard table shape loop construction other positions of being convenient to patient's head or health enter the working region of magnet, have increased the working space of operation.
Hollow in the present embodiment billiard table shape coil is made up of two symmetrical eccentric circular rings along the profile of axis, shown in Fig. 3 b, coil is that the symmetry axis coiling forms with axis 7 in the profile, the minor radius end face B of the right half part 6 of profile and symmetry axis 7 folded acute angles (angle of latitude) are 15 degree, long radius end face A and symmetry axis 7 folded acute angles (angle of latitude) are 75 degree, be that occupied angle of latitude scope is 60 degree, two occupied angle of latitude sums of eccentric circular ring are that angle of strike is 120 degree.Because coil is that symmetry axis distributes axisymmetricly with axis 7, therefore the left-half 5 of coil is symmetrical fully with right half part 6 in this profile, and the angular relationship of left-half 5 and axis 7 is equal to the correlation of right half part 6 coaxial lines 7 fully.This as can be known scheme can produce bigger magnetic field gradient and other less multistage components from calculate, and can also provide bigger watch window simultaneously.
Fig. 4 a is the hollow billiard table shape coil rack profile of the embodiment of the invention, and the effect of its end plates C, D is to provide support in the process of coiling, prevents " race line ".Can see that from Fig. 4 b owing to the radius of D end is held less than C, if the direction of coiling is from C to D, then the process center line in coiling can slide to the D end, therefore, the direction of winding of coil of the present invention is from the minor radius end--D holds to the long radius end--, and C holds.If adopt this winding method of loop construction of multilayer will have a lot of joints, we adopt following double-cake coils method for the joint that reduces coil:
4b with reference to the accompanying drawings in the middle of a lead, at the middle part of D end with the clamping apparatus static line, is pasting the spherical shell face with its half root lead earlier, holds the coiling of enclosing the land around the axis of billiard table shape coil rack from minor radius end plate D end to long radius end plate C.For anti-principal vertical line skid can be before coiling on skeleton or below a layer line surface be coated with last layer glue, can reduce " race line " phenomenons such as " skidding " so effectively.After treating that this half root wire-wound is intact, fixing the end of a thread in the hole of long radius end plate, and then the outer surface that is pasting one deck coil that has wound to the C end from the D end is around other half root lead, but its direction of winding is opposite with preceding half root direction of winding.Like this, two parts of same lead are from D to the C coiling, have avoided the generation of " race line " phenomenon.And single line can be coated with one deck glue around intact back on the surface of coil, and carry out layer insulation once more around two-layer.For superconducting coil, because the working voltage of coil is lower, the general brush ring epoxy resins of interlayer so not only can play insulation but also can play the effect of curing; If working voltage is very high, available insulating varnished silk or other insulation films are done layer insulation for conventional copper conductor; If working voltage is not high, directly uses the insulation solidified paint to be applied to each layer line circle surface and get final product.Then use an other lead around two-layer again, method is the same.The rest may be inferred can finish the coiling work of lattice coil.In order to guarantee the smooth of coil surface, in the process of coiling, also can use clamping apparatus.In sum, by using the method in the present embodiment, both can effectively solve " race line " problems such as " skidding ", and the tieing quantity of lead can have been reduced half again, this has remarkable advantages and meaning more for the magnet that uses the superconducting line coiling.
Claims (5)
1, the superconducting magnet used of a kind of magnetic operation, comprise superconducting coil, cooled cryostat (9) and screen (10), it is characterized in that superconducting coil by large, medium and small three together mutually nested, and the hollow billiard table shape coil (1) of mutually orthogonal placement, (2), (3) are formed; The axis of three coils is respectively the x of rectangular coordinate system, y, and the z axis, the axes intersect of three coils is in a bit; The endosphere radius of the hollow billiard table shape coil (1) during the outer radius of sphere of little hollow billiard table shape coil (2) is slightly less than, in the outer radius of sphere of hollow billiard table shape coil (1) be slightly less than the endosphere radius of big hollow billiard table shape coil (3); Each hollow billiard table shape coil top all has circular hole; Three mutually nested hollow billiard table shape coils constitute 7/8 spherical magnet, and whole spherical magnet places a cooled cryostat (9), cooled cryostat (9) outer wrapping screen (10).
2, the superconducting magnet of using according to the described magnetic operation of claim 1, it is characterized in that described each hollow billiard table shape coil forms by two symmetrical eccentric circular rings along the cross section of axis, wherein each eccentric circular ring two ends formation angle is spent between 70 degree 10, and promptly the angle of strike of each hollow billiard table shape coil is spent between 140 degree 20.
3, the superconducting magnet of using according to the described magnetic operation of claim 1, it is characterized in that described cooled cryostat (9) is one 7/8 spherical Dewars, the outer radius of Dewar is a bit larger tham the outer radius of maximum billiard table shape coil (3) in three coils, and inside radius is slightly less than the inside radius of minimum billiard table shape coil (2).
4, the superconducting magnet of using according to any one described magnetic operation of claim 1 to 3, the spherical cooled cryostat (9) that it is characterized in that described spherical magnet is wrapped with the 7/8 spherical shell screen (10) that a usefulness soft ferromagnetic material is made, and the inside radius of screen (10) is slightly larger than the outer radius of spherical Dewar (9).
5, the winding method of the hollow billiard table shape of the superconducting magnet coil of using according to the described magnetic operation of claim 1, it is characterized in that in the middle of a lead, earlier at the middle part of billiard table shape coil rack (8) minor radius end plate D end with the clamping apparatus static line, pasting the spherical shell face with its half root, the end around the axis of billiard table shape coil rack (8) from minor radius end plate D is to long radius end plate C end one coiling of enclosing the land; Treat that this half root lead after intact, is coated with one deck glue on the surface of coil, and at long radius end plate C end place fixing the end of a thread; And then the outer surface that is pasting one deck coil that has wound to long radius end plate C end from minor radius end plate D end is around other half root lead, but its direction of winding is opposite with preceding half root direction of winding; Be coated with one deck glue around intact back once more on the surface of coil, and carry out layer insulation, then use an other lead around two-layer again, method is the same; The rest may be inferred finishes the coiling work of lattice coil.
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| Application Number | Priority Date | Filing Date | Title |
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| CNB2004100094857A CN100477026C (en) | 2004-08-27 | 2004-08-27 | Superconductor magnet for magnetic surgical operation and coil winding method thereof |
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| CNB2004100094857A CN100477026C (en) | 2004-08-27 | 2004-08-27 | Superconductor magnet for magnetic surgical operation and coil winding method thereof |
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| CN100477026C true CN100477026C (en) | 2009-04-08 |
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Families Citing this family (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100495597C (en) * | 2006-09-30 | 2009-06-03 | 中国科学院电工研究所 | Conductive cooling superconducting magnet system in use for gyrotron |
| CN101256873B (en) * | 2007-12-26 | 2011-02-09 | 中国科学院电工研究所 | Space rotating magnetic field generating apparatus and control method thereof |
| CN101794653B (en) * | 2010-03-12 | 2012-02-29 | 中国科学院电工研究所 | Superconducting magnet generating rotating magnetic field |
| CN102540110B (en) * | 2011-12-19 | 2014-01-22 | 北京卫星环境工程研究所 | Magnetic torque measuring coil assembly |
| EP3125804B1 (en) * | 2014-03-31 | 2019-05-01 | Covidien LP | Hand-held spherical antenna system to detect transponder tagged objects, for example during surgery |
| CN111863377B (en) * | 2020-07-21 | 2021-08-13 | 中国科学技术大学 | Coil structure, coil parameter determination method and device and electronic equipment |
| CN113506668B (en) * | 2021-06-24 | 2024-03-01 | 北京量子信息科学研究院 | Method for generating uniform magnetic field, magnetic field coil, device, apparatus, and storage medium |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6241671B1 (en) * | 1998-11-03 | 2001-06-05 | Stereotaxis, Inc. | Open field system for magnetic surgery |
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Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6241671B1 (en) * | 1998-11-03 | 2001-06-05 | Stereotaxis, Inc. | Open field system for magnetic surgery |
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