JP2714503B2 - Gradient magnetic field coil and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gradient magnetic field coil for generating a gradient magnetic field used in, for example, a magnetic resonance imaging apparatus and a method of manufacturing the same.

[0002]

2. Description of the Related Art FIG. 4 is a cutaway perspective view showing a gantry section of a conventional magnetic resonance imaging apparatus.
Is a patient as a subject, 2 is a patient transport bed, and 3 is disposed so as to surround the patient 1. A uniform for precessing the nuclides of the living tissue of the patient 1 selectively at the Larmor frequency. A magnet 4 for generating a certain constant static magnetic field is disposed inside the magnet 3, and a gradient magnetic field coil for generating a magnetic field having a constant gradient distribution, and 5 is an RF antenna.

Next, the operation of the conventional magnetic resonance imaging apparatus will be described. First, the patient 1 is placed on the patient transport bed 2 and housed inside the magnet 3. Inside the magnet 3 (imaging space), the magnet 3 sets a uniform static magnetic field, and supplies a pulse current which is calculated in advance to the gradient coil 4 to generate a magnetic field having a pulse-like gradient distribution. Superimposed on static magnetic field. Here, the nucleus placed in the static magnetic field H ₀ resonates with a high-frequency magnetic field having a frequency of f ₀ = rH ₀ / 2π (r is a constant called a nuclear magnetic rotation ratio). The static magnetic field is given a tilt in the z direction by the magnetic field coil 4,
When a high-frequency magnetic field having a specific frequency is irradiated, only nuclei on a plane orthogonal to the z-axis at a specific position resonate.

[0004] When a rotating magnetic field having a frequency equal to the Larmor frequency of the specified imaging region of the patient 1 is irradiated from the RF antenna 5, nuclei of the specified imaging region of the patient 1 undergo magnetic resonance, and this magnetic resonance signal is generated. , The distribution of hydrogen atoms in the living body is photographed as a tomographic image.

Next, the structure of the gradient coil 4 will be described. FIG. 5 is a developed view showing a conventional gradient magnetic field coil described in, for example, Japanese Patent Application Laid-Open No. 1-220806. This gradient magnetic field coil 4 has a fingerprint-like coil pattern 6 whose curvature changes as the winding progresses. It is rolled up into a cylinder. FIGS. 6A and 6B are development views of an inner coil and an outer coil of a conventional gradient magnetic field coil described in, for example, Japanese Patent Application Laid-Open No. Sho 62-194842. , An inner coil 7 and a magnet 3 for generating a magnetic field having a constant gradient distribution
And the outer coil 8 for removing the influence of the induced current induced in the structure of the inner and outer coils 7,
In FIG. 8, fingerprint-like coil patterns 7a and 8a whose curvature changes as the winding progresses are formed.

Here, the coil patterns 6, 7a, 8a
As described in, for example, JP-A-1-220806, a flow function (a source or a sink in a region of the flow of the surface current of the gradient coil, that is, a point at which the flow is generated or disappears there). Draw a number of streamlines separated by the size of the step that is going to be described in the graph), cut each closed curve at a certain point, and combine each curve with the next curve to form a spiral It is derived by forming a winding pattern. In addition, the cutting points are substantially on the same straight line, and the conductors brought in from the outside of the coil in order to couple to the position inside the plate of the spiral winding pattern are parallel so that the effect of cutting off the flow is substantially canceled. Preferably, it can be arranged.

Further, as shown in FIGS. 7 (a) and 7 (b) shown in, for example, Japanese Utility Model Application Laid-Open No. 63-120612, a conventional gradient magnetic field coil 4 is provided with a predetermined coil on a bottom surface of a mold 9. A linear conductor 11 is wound along a guide pin 10 provided according to a pattern, and a curing agent 12 having flexibility even after curing is poured into a mold 9 to form a coil material 13 integrated with the conductor 11 into a cylindrical shape. It was manufactured by attaching to the bobbin 14.

[0008] However, in the above conventional manufacturing method,
In order to form a fingerprint-like coil pattern as designed, a large number of guide pins 10 are used, and the production and installation of the guide pins 10 are required, so that the production time becomes longer and the production cost increases. Had been lost.

In the gradient coil manufactured as described above, it is necessary to use a guide pin 10 having a small diameter at a portion of the coil pattern having a small curvature.
The guide pin 10 may be bent or bent because the rigidity of the guide pin 10 cannot be secured, and it is difficult to obtain a desired coil pattern. Even if the rigidity of the guide pin 10 can be secured, the guide pin 10 may be formed on the surface of the conductor 11 by bending stress. Cracks may occur in the enamel insulation film, or cracks may occur in the conductor 11 itself. Further, since the coil pattern shape of the conductor 11 is ensured by the flexible hardener 12, The coil pattern may be deformed due to springback after mounting or bending at the time of attachment to the hobbin 14, and desired output characteristics may not be obtained.

Alternatively, for example, Japanese Patent Application Laid-Open No. 62-19484
As described in Japanese Patent Laid-Open No. 2 (1999) -2005, a copper foil of a printed wiring board to which a copper foil is stuck is formed by etching to form a predetermined coil pattern, and attached to a cylindrical hobbin 14.

However, in the above conventional manufacturing method,
Since the coil pattern is formed by etching,
Although a pattern with design values can be produced with high precision, the current capacity could not be ensured because the copper foil forming the conductor 11 was usually as thin as 2 mm or less and the coil cross-sectional area was small. The gradient magnetic field coil manufactured in this manner is placed in a wide imaging space of, for example, a 35 cm diameter sphere in an ordinary whole-body magnetic resonance imaging apparatus by 0.3 to 1 mm.
It is not possible to secure a current capacity of about several hundred A that needs to be energized to generate a strong magnetic field gradient of about Gauss / cm,
In some cases, desired output characteristics could not be obtained.

[0012]

As described above, in the conventional gradient magnetic field coil, the linear conductor 11 is wound along the guide pins 10 provided on the bottom surface of the mold 9 according to a predetermined coil pattern, and after being cured. A coil material 13 integrated with the conductor 11 by pouring a hardening agent 12 having flexibility into the mold 9
Or the printed wiring board on which the coil pattern is formed by etching is attached to the cylindrical bobbin 14, so that the coil pattern is deformed, and the insulating film of the conductor 11 and cracks are generated on the conductor 11 itself. Or the cross-sectional area of the conductor 11 becomes small, and a predetermined output characteristic cannot be obtained.

As described above, the conventional method of manufacturing a gradient magnetic field coil includes a linear conductor 1 along a guide pin 10 provided on a bottom surface of a mold 9 in accordance with a predetermined coil pattern.
1 is wound, and a hardening agent 12 having flexibility even after hardening is poured into the mold frame 9 and the coil material 13 integrated with the conductor 11 is attached to the cylindrical hobbin 14. There is a problem that the production and the mounting work are required, and the production time becomes longer and the production cost becomes higher.Or, a desired coil pattern is formed by etching the printed wiring board to which the copper foil is attached. After that, since it is mounted on the cylindrical hobbin 14, the current capacity cannot be secured, and there is also a problem that a gradient coil having desired output characteristics cannot be manufactured.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and a fingerprint-like coil pattern can be formed as designed, a large coil cross-sectional area can be obtained, and a gradient magnetic field having a desired gradient can be generated. It is an object of the present invention to obtain a gradient magnetic field coil capable of obtaining a desired output intensity.

The present invention provides a method of manufacturing a gradient magnetic field coil which can generate a gradient magnetic field having a desired gradient and obtain a desired output intensity easily, in a short time and at low cost. The purpose is to:

[0016]

A gradient magnetic field coil according to a first aspect of the present invention comprises a gradient magnetic field coil winding frame, a gradient magnetic field coil, and a gradient magnetic field coil.
Coil attached to a predetermined position on the outer peripheral surface of the coil
Coil with a coil conductor.
The body is formed into a predetermined coil pattern shape from a conductive thin plate.
Of the coil wires covered with the insulation film
Into the outer diameter of the gradient coil winding frame
It is manufactured in a curved state .

[0017] In the method of manufacturing a gradient coil according to the second aspect of the invention, the step (1) to be cut out of the coil wire to a predetermined co-yl pattern from the conductor sheet, coil
Step (2) of coating the outer peripheral surface of the wire with an insulating film;
Laminated and integrated multiple coil strands coated with film
A coil that is curved to the outer diameter of the gradient coil winding frame
Step (3) of manufacturing a conductor, and using a gradient magnetic field
Step of attaching to a predetermined position on the outer peripheral surface of the il reel (4)
And In the above step (3), carp
The outer peripheral surface of the insulating wire is coated with a thermosetting resin,
Inside a formwork having the same outer diameter as the outer peripheral surface of the gradient magnetic field coil form
A plurality of coil wires in a stack, and then heat and heat
The curable resin is cured to integrate multiple coil wires.
In the state of being curved to the outer diameter shape of the gradient coil
This is for producing a conductor. Further, the above step (3)
Has an outer diameter equivalent to the outer peripheral surface of the gradient coil winding
A plurality of coil wires are stacked and arranged in a mold, and then the
Inject the adhesive resin into the
Outer diameter of gradient coil winding by integrating coil wire
This is for producing a coil conductor in a curved state.

[0018]

In the gradient magnetic field coil according to the first aspect of the present invention, the coil element wire is preliminarily formed from a thin conductor plate .
Because it is formed into coils pattern shape, laminated together can be formed with high accuracy in a coil pattern of the design value the coil wire, can be prevented pattern deformation of the coil wires due to bending during mounting, further coil wire Unite,
Preliminarily curved to the outer diameter of the gradient coil winding
Since the coil conductor of the present invention is manufactured , a desired coil cross-sectional area can be easily secured, and a gradient magnetic field having a desired output intensity can be generated.

In the method for manufacturing a gradient magnetic field coil according to a second aspect of the present invention, after a coil wire is cut out of a conductor thin plate into a predetermined coil pattern shape , an insulating film is formed on an outer peripheral surface of the coil wire. , Insulation coating
The multiple coil strands are stacked and integrated to form a gradient magnetic field coil.
Manufactures coil conductors that are curved to the outer diameter of the coil bobbin
Then, the coil conductor is fixed on the outer peripheral surface of the gradient coil winding frame .
Since it is installed at the position , the coil pattern of the coil wire can be formed according to the design value, the pattern deformation of the coil wire due to bending at the time of installation can be prevented, the coil cross-sectional area can be secured, and the desired output intensity gradient A gradient magnetic field coil capable of generating a magnetic field can be manufactured simply, in a short time and at low cost. In addition, the outer surface of the insulation film of the coil wire is heat-cured.
Coated with a conductive resin, the same as the outer peripheral surface of the gradient coil winding frame.
Multiple coil strands are stacked and arranged in a mold having an outer diameter
And then heat it to cure the thermosetting resin,
The coil conductor is integrated to make the coil conductor
In this case, the core in the state of being curved to the outer diameter shape of the gradient coil
The il conductor can be easily manufactured. Also, gradient magnetic
In a formwork having the same outer diameter as the outer peripheral surface of the
Lay out several coil strands, and then glue the
Oil, and the adhesive resin is cured to form a plurality of coil elements.
Since the coil conductor is made by integrating the wires,
The coil conductor that is curved to the outer diameter of the field coil winding
Can be made.

[0020]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. Embodiment 1 FIG. 1 (a) and 1 (b) are a perspective view and a sectional view of a main part of a gradient magnetic field coil showing a first embodiment of the present invention. In the figure, reference numeral 20 denotes a synthetic resin such as a glass epoxy resin or a phenol resin. A cylindrical gradient magnetic field coil winding frame, 21 is a coil conductor having a desired coil pattern attached to the outer peripheral surface of the gradient magnetic field coil winding frame 20, and 22 is a coil formed in a desired fingerprint coil pattern shape. The wires 23 are insulating films formed by applying an electric insulating agent such as polyvinyl formal (PVF) on the surface of the coil wires 22, and 24 is formed by applying butyral or the like to the surface of the insulating film 23. It is a thermosetting adhesive.

Next, a method of manufacturing the gradient coil according to the first embodiment will be described with reference to FIGS. First, using a control cutting machine, for example, a wire cut, a conductor thin plate 25 made of copper or the like having a thickness of 1 mm is cut into a fingerprint coil pattern shape having a design value with high processing accuracy.
As shown in FIG. 2A, a coil wire 22 having a desired coil pattern shape is manufactured. Next, after applying PVF to the surface of the coil element wire 22 to form an insulating film 23, butyral is applied to form a thermosetting adhesive 24.

Thereafter, as shown in FIG. 2B, an insulating film 23 and a thermosetting adhesive 24 are formed in a mold 26 having an outer diameter equal to the outer peripheral surface of the gradient coil winding frame 20. The coil wires 22 are stacked and arranged so as to obtain a predetermined energized cross-sectional area, and heated to 100 ° C. to thermally cure the thermosetting adhesive 24, and each of the coil wires 22 is electrically insulated from each other. In this state, the coil conductor 21 which is curved and integrated into the outer diameter shape of the gradient coil winding frame 20 is manufactured.
Further, as shown in FIG. 2C, the coil conductor 21 is attached to a predetermined position on the outer peripheral surface of the gradient coil winding frame 20 with an adhesive or the like, thereby producing a gradient coil.

The gradient coil manufactured as described above is
It is used in the magnetic resonance imaging apparatus shown in FIG. 4 and operates similarly to the conventional gradient magnetic field coil 4.

According to the gradient magnetic field coil according to the first embodiment, since the coil wire 22 is cut out of the conductor thin plate 25 in advance into a fingerprint coil pattern shape having design values, the coil pattern shape accuracy is improved. A magnetic field having a desired gradient distribution can be obtained, and a plurality of coil strands 22 are laminated, so that a current-carrying cross-sectional area of the coil conductor 21 can be secured, a desired magnetic field strength can be obtained, and the laminated coil can be obtained. Since the wires 22 are electrically insulated from each other by the insulating film 23, the effect that eddy current is less generated and loss can be reduced is obtained.

Further, according to the method of manufacturing the gradient magnetic field coil according to the first embodiment, the coil wire 22 is cut out of the conductor thin plate 25 in advance into a fingerprint-like contour pattern having a design value. After coating the insulating film 23 and the thermosetting adhesive 24, a predetermined number of coil strands 22 are integrated in a state of being curved to the outer diameter of the gradient coil winding frame 20 to form a coil conductor 21. Since the conductor 21 is mounted at a predetermined position on the outer peripheral surface of the gradient coil winding frame 20, a gradient magnetic field having a desired strength and gradient can be generated, and a gradient magnetic field coil with low loss can be manufactured easily, in a short time and at low cost. There is an effect that can be.

Embodiment 2 FIG. FIG. 3 is a perspective view of a gradient coil showing a second embodiment of the present invention. In FIG. 3, reference numeral 27 denotes an outer peripheral coil winding concentrically arranged outside the gradient coil winding 20; The coil conductor has a fingerprint-like coil pattern that is attached to the outer peripheral surface and shields an induced current induced in the structure of the magnet 3.

Next, a method of manufacturing the gradient coil according to the second embodiment will be described. First, in the same manner as in the first embodiment, a gradient magnetic field coil bobbin 20 to which a coil conductor 21 for generating a magnetic field having a constant gradient distribution is manufactured.
Next, similarly to the coil conductor 21, the coil wire is cut out from the conductor thin plate 25 in a fingerprint-like coil pattern shape for shielding the induced current induced in the structure of the magnet 3 in advance, and an insulating film and an insulating film are formed on the surface of the coil wire. After applying the thermosetting adhesive, this coil wire is placed in a mold having the same outer diameter as the outer peripheral surface of the outer peripheral coil form 27, and the coil wire on which the insulating film and the thermosetting adhesive are formed is fixed. Are stacked and heated so as to obtain a current-carrying cross-sectional area, and the thermosetting adhesive is heat-cured, and the outer diameter of the outer coil winding frame 27 is kept in a state where the coil wires are electrically insulated from each other. The coil conductor 28 which is curved and integrated is manufactured.

Thereafter, the coil conductor 28 is bonded and fixed to a predetermined position on the outer peripheral surface of the outer peripheral coil form 27. Therefore, the gradient magnetic field coil is manufactured by concentrically arranging the gradient coil winding frame 20 and the outer peripheral coil winding frame 27. The gradient magnetic field coil produced in this way produces a magnetic field having a constant gradient distribution and a gradient magnetic field coil that eliminates the influence of the induced current induced in the structure of the magnet 3.

Embodiment 3 FIG. In the first embodiment, after the insulating film 23 and the thermosetting adhesive 24 are coated on the surface of the coil wire 22 cut out from the conductor thin plate 25 into a predetermined fingerprint coil pattern shape, the outer periphery of the gradient magnetic field coil winding frame 20 is formed. A plurality of coil strands 22 are stacked and arranged in a mold 26 having an outer diameter equal to the diameter, heated and the thermosetting adhesive 24 is thermally cured to laminate and integrate the plurality of coil strands 22 to form a coil. In the third embodiment, the conductor 21 is manufactured. In the third embodiment, the surface of the coil wire 22 cut out from the conductor thin plate 25 into a predetermined fingerprint coil pattern shape is coated with the insulating film 23, and then the gradient magnetic field coil is wound. A plurality of coil strands 22 are stacked and arranged in a mold 26 having an outer diameter equal to the outer diameter of the frame 20 to form an adhesive resin.
A plurality of coil strands 22 are bound and integrated with the adhesive 24 to produce a coil conductor 21 curved to the outer diameter of the gradient coil winding frame 20, and the same effect is exerted.

Embodiment 4 FIG. In the first embodiment, after the insulating film 23 and the thermosetting adhesive 24 are coated on the surface of the coil wire 22 cut out from the conductor thin plate 25 into a predetermined fingerprint coil pattern shape, the outer periphery of the gradient magnetic field coil winding frame 20 is formed. A plurality of coil strands 22 are stacked and arranged in a mold 26 having an outer diameter equal to the diameter, heated and the thermosetting adhesive 24 is thermally cured to laminate and integrate the plurality of coil strands 22 to form a coil. In the fourth embodiment, the conductor 21 is produced. In the fourth embodiment, the surface of the coil wire 22 cut out from the conductor thin plate 25 into a predetermined fingerprint coil pattern shape is coated with the insulating film 23, and then the gradient magnetic field coil is wound. A plurality of coil strands 22 are stacked and arranged in a mold 26 having an outer diameter equal to the outer diameter of the frame 20, and contact with the mold 26.
An epoxy resin as an adhesive resin is injected and cured to integrate the plurality of coil wires 22 into a gradient coil winding frame 20.
The same effect can be obtained by manufacturing the arc-shaped coil conductor 21 having a curved outer diameter.

In each of the above embodiments, the coil wire 22 is cut out of the conductor thin plate 25 into a coil pattern shape of a design value by wire cutting as a controlled cutting machine.
A cutting machine using a laser or a water jet may be used.

In each of the above embodiments, the coil wire 22
Is formed of copper, but the material may be a conductive material, for example, aluminum.

Further, in each of the above embodiments, the coil conductor 2
One coil pattern draws a number of streamlines separated by a predetermined step-shaped dimension of the flow function, cuts each closed curve at a certain point, and combines each curve with the next curve to form a spiral winding. Although a fingerprint-like pattern derived by forming a line pattern is used, the present invention is not limited to this coil pattern. For example, the same effect can be obtained by using a coil pattern described in JP-A-62-143012. Play.

[0034]

Since the present invention is configured as described above, it has the following effects.

A gradient magnetic field coil according to a first aspect of the present invention is a coil mounted on an outer peripheral surface of a gradient coil winding frame.
Il conductor is converted from a conductor thin plate into a predetermined coil pattern shape.
A plurality of coil wires formed and covered with an insulation film
Laminated and integrated beforehand the outer diameter of the gradient coil winding frame
Since it is manufactured in a curved shape, the coil pattern shape of the coil element wire can be formed with high precision, the cross-sectional area of current can be secured, and a magnetic field having a desired gradient distribution with a desired output intensity can be generated. .

[0036] In the method of manufacturing a gradient coil according the second aspect of the invention, the step (1) to be cut out of the coil wire from the conductor sheet in a predetermined co-yl pattern, coil
Step (2) of coating the outer peripheral surface of the wire with an insulating film;
Laminated and integrated multiple coil strands coated with film
A coil that is curved to the outer diameter of the gradient coil winding frame
Step (3) of manufacturing a conductor, and using a gradient magnetic field
Step of attaching to a predetermined position on the outer peripheral surface of the il reel (4)
Since they have bets, the gradient magnetic field coil for generating a magnetic field of desired gradient distribution in the desired output intensity, conveniently in a short time, can be manufactured at low cost. Also, the above process
(3) A thermosetting resin is applied to the outer peripheral surface of the insulation film of the coil wire.
Grease, and the same outer diameter as the outer peripheral surface of the gradient coil winding frame
A plurality of coil wires are stacked and arranged in a mold having
After heating, the thermosetting resin is cured to form multiple coils.
Integrates the wires and curves to the outer diameter shape of the gradient coil winding frame
Because we are trying to make a coil conductor in the state of
A coil that is curved to the outer diameter of the gradient coil winding frame
Conductors can be easily manufactured. Further, the step (3) is inclined.
Inside a formwork having the same outer diameter as the outer peripheral surface of the gradient magnetic field coil form
A plurality of coil strands in a stack, and then
Inject resin, cure the adhesive resin, and
Integrated into the outer diameter of the gradient coil winding
I try to make a coil conductor in a bent state
In this case, the core in the state of being curved to the outer diameter shape of the gradient coil
An il conductor can be easily manufactured.

[Brief description of the drawings]

FIG. 1 (a) is a perspective view of a gradient coil showing a first embodiment of the present invention, and FIG. 1 (b) is a sectional view of a main part of the gradient coil showing a first embodiment of the present invention.

FIGS. 2 (a) to 2 (c) each show Embodiment 1 of the present invention.
It is process drawing of the manufacturing method of a gradient magnetic field coil which shows this.

FIG. 3 is a perspective view of a gradient coil showing a second embodiment of the present invention.

FIG. 4 is a cutaway perspective view showing a gantry section of a conventional magnetic resonance imaging apparatus.

FIG. 5 is a development view showing an example of a conventional gradient magnetic field coil.

6 (a) and 6 (b) are developed views showing an inner coil and an outer coil of a conventional gradient coil, respectively.

FIGS. 7A and 7B are process diagrams illustrating a conventional method of manufacturing a gradient coil.

[Explanation of symbols]

 Reference Signs List 20 Gradient coil winding frame 21 Coil conductor 22 Coil strand 25 Conductor thin plate

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiki Demaru 651 Tenwa, Ako City Mitsubishi Electric Corporation Ako Works (72) Inventor Takeshi Kataoka 651 Tenwa Ako City Inside Mitsubishi Electric Ako Works (56 ) References JP-A-4-337614 (JP, A)

Claims (4)

(57) [Claims] And 1. A gradient coil winding frame, the gradient magnetic field co
A coil attached at a predetermined position on the outer peripheral surface of the il reel
A gradient magnetic field coil comprising: a conductor;
The body is formed into a predetermined coil pattern shape from a conductive thin plate.
Of the coil wires covered with the insulation film
And the outer diameter of the gradient coil
A gradient coil manufactured in a curved state . Wherein the step (1) to be cut out of the coil wire to a predetermined co-yl pattern from the conductive sheet, the coil wire
(2) coating an outer peripheral surface with an insulating film, and an insulating film
Is laminated and integrated a plurality of the coil element wires coated
A coil that is curved to the outer diameter of the gradient coil winding frame
A step (3) of producing a conductor;
Attach to a predetermined position on the outer peripheral surface of the gradient magnetic field coil winding frame
(4) A method for manufacturing a gradient magnetic field coil, comprising: 3. The step (3) includes the step of forming an insulating film on the coil wire.
The outer peripheral surface is coated with a thermosetting resin,
A plurality of the coils are placed in a mold having the same outer diameter as the outer peripheral surface.
And then heating the thermosetting resin
To cure and integrate a plurality of the coil strands,
A coil that is curved to the outer diameter of the gradient coil winding frame
3. The gradient magnet according to claim 2, wherein the conductor is made.
Method of manufacturing field coils. 4. The method according to claim 1, wherein the step (3) is performed outside the gradient coil winding frame.
Multiple coil wires in a formwork having the same outer diameter as the peripheral surface
Are laminated and then an adhesive resin is injected into the mold, and the
The resin is cured to integrate the plurality of coil strands.
In the state of being curved to the outer diameter shape of the gradient coil winding frame.
3. The coil conductor according to claim 2, wherein the coil conductor is manufactured.
Manufacturing method of gradient magnetic field coil.