阅读说明：本技术 用于梯度线圈的带场替换方法 (Band replacement method for gradient coil ) 是由 韩振宇 何钧 林海洋 李文彬 于 2020-07-14 设计创作，主要内容包括：本发明公开了一种用于梯度线圈的带场替换方法,包括步骤：1：不降低超导磁体(3)磁场强度并在两端设第一移动件(1)和固定件(5)；2：连接件(4)设在第一移动件和固定件间；3：第二移动件(8)装在连接件上并移动；4：第二移动件顶起梯度线圈(2)并移动；5：移到第一移动件上方时,降低连接件使梯度线圈落在第一移动件上；6：卸下连接件和第二移动件；7：更换新梯度线圈并移回超导磁体一端；8：安装连接件和第二移动件；9：第二移动件顶起新梯度线圈并移动；10：移动到位后,降低连接件,卸下连接件和第二移动件、第一移动件和固定件。本发明能在超导磁体不降低磁场的情况下替换梯度线圈,节约降低磁场和励磁升场的时间。(The invention discloses a band field replacement method for a gradient coil, which comprises the following steps: 1: the magnetic field intensity of the superconducting magnet (3) is not reduced, and a first moving part (1) and a fixed part (5) are arranged at two ends; 2: the connecting piece (4) is arranged between the first moving piece and the fixed piece; 3: the second moving member (8) is mounted on the connecting member and moves; 4: the second moving piece jacks up the gradient coil (2) and moves; 5: when the gradient coil moves to the upper part of the first moving part, the connecting piece is lowered to enable the gradient coil to fall on the first moving part; 6: detaching the connecting piece and the second moving piece; 7: replacing a new gradient coil and moving back to one end of the superconducting magnet; 8: mounting the connecting piece and the second moving piece; 9: the second moving piece jacks up the new gradient coil and moves; 10: after the first moving part and the second moving part are moved in place, the connecting part is lowered, and the connecting part, the second moving part, the first moving part and the fixing part are detached. The invention can replace the gradient coil under the condition that the superconducting magnet does not reduce the magnetic field, and saves the time for reducing the magnetic field and exciting the field.)

1. A method of band replacement for a gradient coil, characterized by: the method comprises the following steps:

step 1: a first moving part (1) is arranged at one end of the superconducting magnet (3) without reducing the magnetic field intensity of the superconducting magnet (3), and a fixing part (5) is fixedly arranged at the other end of the superconducting magnet (3);

step 2: platforms (6) are arranged at the tops of the first moving part (1) and the fixed part (5), the platforms (6) are positioned at horizontal positions, and the connecting parts (4) are movably connected to the two platforms (6) to enable the connecting parts (4) to penetrate through the gradient coil (2);

and step 3: the second moving part (8) is arranged on the connecting part (4) so that the second moving part (8) can move along the connecting part (4), and the second moving part (8) is positioned in the gradient coil (2);

and 4, step 4: the connecting piece (4) is lifted to enable the second moving piece (8) to jack up the gradient coil (2), and the gradient coil (2) is driven to move towards the first moving piece (1) along the connecting piece (4) through the second moving piece (8);

and 5: when the gradient coil (2) moves above the first moving part (1), the connecting piece (4) is lowered to enable the gradient coil (2) to fall on the first moving part (1);

step 6: the connecting piece (4) and the second moving piece (8) are disassembled, the gradient coil (2) is moved through the first moving piece (1), and the dismounting of the gradient coil (2) in a belt field is completed;

and 7: changing the gradient coil (2) on the first moving member (1) at a place far away from the magnetic field, and moving a new gradient coil (2) to one end of the superconducting magnet (3) through the first moving member (1);

and 8: mounting the connecting piece (4) on the platform (6), mounting the second moving piece (8) on the connecting piece (4), and enabling the second moving piece (8) to be positioned in the new gradient coil (2);

and step 9: the connecting piece (4) is lifted up to enable the second moving piece (8) to jack up the new gradient coil (2), and the second moving piece (8) drives the new gradient coil (2) to move towards the superconducting magnet (3) along the connecting piece (4);

step 10: and after the new gradient coil (2) is moved in place, lowering the connecting piece (4) to separate the second moving piece (8) from the new gradient coil (2), detaching the connecting piece (4) and the second moving piece (8), removing the first moving piece (1) and the fixing piece (5), and completing the field installation of the new gradient coil (2).

2. The band replacement method for a gradient coil as set forth in claim 1, wherein: the two ends of the connecting piece (4) are respectively installed on the reserved bolt holes of the two platforms (6) through a plurality of adjusting bolts (7), and the connecting piece (4) is lifted up and down through the threaded rotation of the adjusting bolts (7) in the reserved bolt holes.

3. The band replacement method for a gradient coil as set forth in claim 2, wherein: the adjusting bolt (7) is made of copper or aluminum.

4. The band replacement method for a gradient coil as set forth in claim 1, wherein: the length of the first moving part (1) is not less than that of the gradient coil (2), one end of the connecting part (4) extends to the upper part of the first moving part (1), and the length of the connecting part (4) above the first moving part (1) is not less than that of the gradient coil (2).

5. The band replacement method for a gradient coil according to claim 1 or 4, characterized in that: the length direction of the connecting piece (4) is parallel to the axial direction of the gradient coil (2).

6. The band replacement method for a gradient coil according to claim 1 or 4, characterized in that: the top of the first moving part (1) is provided with an arc-shaped base (11), so that the arc-shaped bottom surface of the gradient coil (2) is matched and attached to the surface of the arc-shaped base (11).

7. The band replacement method for a gradient coil as set forth in claim 1, wherein: the first moving piece (1), the connecting piece (4), the fixing piece (5), the platform (6) and the second moving piece (8) are all made of copper or aluminum.

Technical Field

The invention relates to a maintenance method of a magnetic resonance imaging system, in particular to a band field replacement method for a gradient coil.

Background

The magnetic resonance imaging technology is an advanced medical imaging technology, has no harm to human bodies, and is widely applied to diagnosis and corresponding scientific research of diseases of all parts of human bodies in the field of clinical medicine. A magnetic resonance imaging system comprises components of a magnet, a gradient system (gradient coils and gradient amplifiers), a radio frequency link (radio frequency transmit coils, radio frequency receive coils, radio frequency amplifiers, etc.), a spectrometer, a computer, etc. The magnet is the most basic component of a magnetic resonance system and is used to generate a uniform background magnetic field. The method is divided into three types according to the principle: permanent magnets, normally conducting magnets, and superconducting magnets. In either case, during normal operation of magnetic resonance, there is a strong magnetic field (low-field magnetic resonance system) or a strong magnetic field (superconducting magnet) both inside and around the magnet, and any material with magnetic properties will be attracted. Taking the most common superconducting magnet on the market at present as an example, the field strength is generally 1.5T or 3.0T, the surrounding magnetic field is very strong, and the most common iron and stainless steel metal products are easily attracted by the surrounding magnetic field. In the past, there have been medical accidents caused by the fact that a patient's wheelchair and a gas cylinder are sucked by a superconducting magnet. When magnetic resonance scanning is carried out, a patient cannot wear metal objects including a cardiac pacemaker absolutely, and even if the metal is nonmagnetic, the patient may feel uncomfortable due to the thermal effect generated by the eddy current effect.

In magnetic resonance imaging systems, the magnetic gradient fields essentially spatially encode the magnetic resonance signals, so that the position information corresponds to the signals obtained from the magnetic resonance system. The gradient magnetic field is generated by a gradient coil, generally the common cylindrical gradient coil of a 1.5T horizontal field superconducting magnet magnetic resonance system is arranged between a superconducting magnet and a radio frequency transmitting coil, is mainly made of a copper wire, a water cooling pipe and resin, has the weight of about 700KG, cannot be directly installed and disassembled manually, and needs to utilize large equipment such as a forklift. However, almost all forklifts are made of stainless steel with strong magnetism, and under the condition that a superconducting magnet works normally, the equipment can be attracted by the magnet and cannot work, and even accidents such as magnetic field quenching and the like are caused. Therefore, in general, when a gradient coil of a magnetic resonance system is in failure and needs to be replaced, hundreds of amperes of current in the superconducting magnet must be slowly reduced to zero to enable the superconducting magnet to not carry any magnetic field, then a forklift is used for removing the failed gradient coil, a new gradient coil is installed, and the current is slowly increased to hundreds of amperes of normal operation. The whole process of replacing the gradient coil needs two to three days, the magnetic resonance system of a common large hospital is fully arranged, and the patient can be scanned basically in about two weeks. This replacement time is therefore a significant waste of medical time for the hospital and may delay the patient's condition.

Disclosure of Invention

The invention aims to provide a field replacement method for a gradient coil, which can replace the gradient coil without reducing the magnetic field of a superconducting magnet to zero and save the time for reducing the magnetic field and exciting the field.

The invention is realized by the following steps:

a band replacement method for a gradient coil, comprising the steps of:

step 1: the method comprises the following steps that a first moving part is arranged at one end of a superconducting magnet without reducing the magnetic field intensity of the superconducting magnet, and a fixing part is fixedly arranged at the other end of the superconducting magnet;

step 2: the tops of the first moving piece and the fixed piece are respectively provided with a platform, the platforms are in a horizontal position, and the two platforms are movably connected with a connecting piece, so that the connecting piece penetrates through the gradient coil;

and step 3: mounting a second moving member on the connecting member so that the second moving member can move along the connecting member, the second moving member being located within the gradient coil;

and 4, step 4: the connecting piece is lifted to enable the second moving piece to jack up the gradient coil, and the second moving piece drives the gradient coil to move towards the first moving piece along the connecting piece;

and 5: when the gradient coil moves above the first moving part, the connecting piece is lowered to enable the gradient coil to fall on the first moving part;

step 6: the connecting piece and the second moving piece are disassembled, and the gradient coil is moved through the first moving piece, so that the field disassembly of the gradient coil is completed;

and 7: changing the gradient coil on the first moving part at a place far away from the magnetic field, and moving a new gradient coil to one end of the superconducting magnet through the first moving part;

and 8: mounting the connecting piece on the platform, and mounting the second moving piece on the connecting piece to enable the second moving piece to be positioned in the new gradient coil;

and step 9: lifting the connecting piece to enable the second moving piece to jack up the new gradient coil, and driving the new gradient coil to move towards the inside of the superconducting magnet along the connecting piece through the second moving piece;

step 10: and after the new gradient coil moves in place, lowering the connecting piece to separate the second moving piece from the new gradient coil, detaching the connecting piece and the second moving piece, and removing the first moving piece and the fixing piece to complete the band-field installation of the new gradient coil.

The two ends of the connecting piece are respectively installed on the reserved bolt holes of the two platforms through a plurality of adjusting bolts, and the connecting piece ascends and descends through the threaded rotation of the adjusting bolts in the reserved bolt holes.

The adjusting bolt is made of copper or aluminum.

The length of the first moving part is not less than that of the gradient coil, one end of the connecting piece extends to the upper part of the first moving part, and the length of the connecting piece above the first moving part is not less than that of the gradient coil.

The length direction of the connecting piece is parallel to the axial direction of the gradient coil.

The top of first moving member be equipped with the arc base, make the arc bottom surface of gradient coil and the surface matching laminating of arc base.

The first moving piece, the connecting piece, the fixing piece, the platform and the second moving piece are all made of copper or aluminum.

According to the invention, under the condition that the magnetic field intensity of the superconducting magnet is not reduced, the gradient coil is loaded, moved out and loaded in through the second moving part and the connecting part, and the gradient coil is moved and replaced through the first moving part, so that the replacement efficiency of the gradient coil is greatly improved, and the maintenance time of a magnetic resonance system is reduced.

Drawings

FIG. 1 is a schematic illustration of a gradient coil removed using the field-replacement method for a gradient coil of the present invention;

FIG. 2 is a front view of FIG. 1;

fig. 3 is a side view of fig. 1.

In the figure, 1 a first moving part, 11 an arc-shaped base, 12 universal wheels, 2 gradient coils, 3 superconducting magnets, 4 connecting pieces, 5 fixed parts, 6 platforms, 7 adjusting bolts and 8 a second moving part.

Detailed Description

The invention is further described with reference to the following figures and specific examples.

Referring to fig. 1 to 3, a method for replacing a band field of a gradient coil includes the following steps:

step 1: the first moving element 1 is provided at one end of the superconducting magnet 3 and the stator 5 is fixedly provided at the other end of the superconducting magnet 3 without reducing the magnetic field strength of the superconducting magnet 3.

Step 2: the tops of the first moving part 1 and the fixing part 5 are both provided with a platform 6, the platform 6 is positioned at a horizontal position, and the connecting parts 4 are movably connected on the two platforms 6, so that the connecting parts 4 penetrate through the gradient coil 2.

The two ends of the connecting piece 4 are respectively installed on the reserved bolt holes of the two platforms 6 through a plurality of adjusting bolts 7, and the connecting piece 4 ascends and descends through the threaded rotation of the adjusting bolts 7 in the reserved bolt holes to adjust the height of the connecting piece 4.

The length of the first moving part 1 is not less than that of the gradient coil 2, one end of the connecting part 4 extends to the upper part of the first moving part 1, and the length of the connecting part 4 above the first moving part 1 is not less than that of the gradient coil 2, so that the gradient coil 2 is ensured to have enough moving-out distance and stably fall on the first moving part 1.

The length direction of the connecting piece 4 is parallel to the axial direction of the gradient coil 2, so that the gradient coil 2 is ensured to move along the axial direction, and the damage to the superconducting magnet caused by accidents such as collision, friction and the like is avoided.

And step 3: the second moving member 8 is mounted on the connecting member 4 through a pulley and a guide rail so that the second moving member 8 can move along the connecting member 4 through the pulley and the guide rail, and the second moving member 8 is located in the gradient coil 2.

And 4, step 4: the connecting piece 4 is lifted through the rotation of the adjusting bolt 7, the second moving piece 8 jacks up the gradient coil 2, the weight of the gradient coil 2 is borne by the second moving piece 8, and the second moving piece 8 drives the gradient coil 2 to move towards the first moving piece 1 along the connecting piece 4.

And 5: when the gradient coil 2 moves to the upper part of the first moving part 1, the connecting piece 4 is lowered through the rotation of the adjusting bolt 7, so that the bottom of the gradient coil 2 falls on the first moving part 1, and the weight of the gradient coil 2 is completely born by the first moving part 1.

The top of first moving member 1 be equipped with arc base 11, make the arc bottom surface of gradient coil 2 and the surface matching laminating of arc base 11, ensure gradient coil 2 and place stability on first moving member 1.

Step 6: the connecting piece 4 and the second moving piece 8 are detached, and the gradient coil 2 is moved by the first moving piece 1, namely the field detachment of the gradient coil 2 is completed.

And 7: the gradient coil 2 on the first moving element 1 is replaced by a device such as a forklift at a location away from the magnetic field, and the new gradient coil 2 is moved to one end of the superconducting magnet 3 by the first moving element 1.

And 8: the connecting piece 4 is arranged on the platform 6 through the adjusting bolt 7, and the second moving piece 8 is arranged on the connecting piece 4 through the pulley and the guide rail, so that the second moving piece 8 is positioned in the new gradient coil 2.

And step 9: the connecting piece 4 is lifted through the threaded rotation of the adjusting bolt 7, so that the second moving piece 8 jacks up the new gradient coil 2, the weight of the new gradient coil 2 is borne by the second moving piece 8, and the new gradient coil 2 is driven by the second moving piece 8 to move towards the inside of the superconducting magnet 3 along the connecting piece 4.

Step 10: after the new gradient coil 2 is moved in place, the connecting piece 4 is lowered through the threaded rotation of the adjusting bolt 7, so that the second moving piece 8 is separated from the new gradient coil 2, the connecting piece 4 and the second moving piece 8 are disassembled, the first moving piece 1 and the fixing piece 5 are removed, and the field installation of the new gradient coil 2 is completed.

The first moving part 1, the connecting part 4, the fixing part 5, the platform 6, the adjusting bolt 7 and the second moving part 8 are all made of copper or aluminum materials, and can also be made of other non-magnetic materials, so that any part is not attracted by a magnetic field in the replacement process, and has enough mechanical strength to bear the weight of the gradient coil 2. The bearing capacity of the whole device consisting of the first moving part 1, the connecting part 4, the fixing part 5, the platform 6, the adjusting bolt 7 and the second moving part 8 can reach about 1.5 tons.

The fixing element 5 is fixed in the whole replacement process, and the bearing capacity of the fixing element is about 1 ton, so that the weight of the gradient coil 2 can be stably borne.

The first moving part 1 can adopt a cart with a universal wheel 12 at the bottom, so that the cart is convenient to move and turn, and the universal wheel 12 has a self-locking function, so that the cart can be stably arranged at one end of the superconducting magnet 3 when the old gradient coil 2 is moved out and the new gradient coil 2 is moved in.

At least two adjusting bolts 7 are arranged on the platform 6, so that the balance of the lifting and the lowering of the connecting piece 4 is ensured.

The second moving member 8 may be a trolley with a pulley at the bottom, and the second moving member 8 is stably moved along a guide rail on the connecting member 4 by the pulley for moving out or in the gradient coil 2. The top of the second moving part 8 can be made into a cambered surface structure so that the cambered surface structure can be attached to the inner wall of the gradient coil 2, and stable support for the gradient coil 2 is ensured.

The present invention is not limited to the above embodiments, and any modifications, equivalent replacements, improvements, etc. within the spirit and principle of the present invention should be included in the protection scope of the present invention.