JPH03162831A - Nuclear magnetic resonance device - Google Patents
Nuclear magnetic resonance deviceInfo
- Publication number
- JPH03162831A JPH03162831A JP1302163A JP30216389A JPH03162831A JP H03162831 A JPH03162831 A JP H03162831A JP 1302163 A JP1302163 A JP 1302163A JP 30216389 A JP30216389 A JP 30216389A JP H03162831 A JPH03162831 A JP H03162831A
- Authority
- JP
- Japan
- Prior art keywords
- sound
- magnetic field
- deformation
- gradient magnetic
- proof
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000005481 NMR spectroscopy Methods 0.000 title claims description 17
- 238000001514 detection method Methods 0.000 claims description 13
- 230000005540 biological transmission Effects 0.000 abstract description 2
- 230000010355 oscillation Effects 0.000 abstract 3
- 230000003068 static effect Effects 0.000 description 6
- 238000010586 diagram Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000007789 sealing Methods 0.000 description 2
- 208000019901 Anxiety disease Diseases 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- 239000011358 absorbing material Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000036506 anxiety Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 239000011491 glass wool Substances 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- 238000002955 isolation Methods 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000004575 stone Substances 0.000 description 1
- 230000001629 suppression Effects 0.000 description 1
Landscapes
- Magnetic Resonance Imaging Apparatus (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は、核磁気共鳴装置における傾斜磁場発生用コイ
ルが発生する振動及び騒音を抑制するようにした構造に
関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a structure for suppressing vibrations and noise generated by gradient magnetic field generating coils in a nuclear magnetic resonance apparatus.
従来の医療用核磁気共鳴装置では、特開昭63−246
146号公報に記載されているように,筒状の静磁場発
生装置内に筒状の真空容器を配置している.そして,こ
の真空容器内には支持体を介して傾斜磁場発生コイルが
収納されている。In the conventional medical nuclear magnetic resonance apparatus, Japanese Patent Application Laid-Open No. 63-246
As described in Publication No. 146, a cylindrical vacuum container is placed inside a cylindrical static magnetic field generator. A gradient magnetic field generating coil is housed within this vacuum container via a support.
また,真空容器は、径の異なる第一,第二の筒状体をも
ち、その軸方向両端部を、それぞれ、管状封止機構によ
り封止している.この一つの封止機構からは真空容器内
12に挿通してなるパイプが導出されており、その運転
により容器内を真空状態とすることができる.
この様な構成により,運転に伴って発生する傾斜磁場コ
イルの振動,及び、その騒音は容器外に伝達せず,内部
に配置される被検者は騒音を聴音しないとなっていた。Further, the vacuum container has first and second cylindrical bodies having different diameters, and both axial ends of the cylindrical bodies are each sealed by a tubular sealing mechanism. A pipe inserted into the vacuum container 12 is led out from this one sealing mechanism, and by operating the pipe, the inside of the container can be brought into a vacuum state. With this configuration, the vibrations of the gradient magnetic field coils generated during operation and the noise thereof are not transmitted to the outside of the container, and the subjects placed inside the container do not hear the noise.
上記従来技術における核磁気共鳴装置では、傾斜磁場発
生用コイルという大きなコイルを真空容器内に配置する
という点について考慮がされておらず、実際の加工の困
難さと,システムが大型化してしまい被検査者に多大な
圧迫感を与えるという問題がある。In the above-mentioned conventional nuclear magnetic resonance apparatus, no consideration was given to the placement of a large coil called a gradient magnetic field generation coil in a vacuum container, which made the actual processing difficult and the system large. There is a problem in that it gives people a great sense of pressure.
本発明は、被検査者に圧迫感を与えることなく,傾斜磁
場コイルが発生する振動、及び、騒音を抑制し被検査者
の検査状態を良好にした核磁気共鳴装置を提供すること
にある.
〔課題を解決するための手段)
本発明は上記目的を達成するために,円筒空間に均一な
高磁場を供給する強磁場発生手段と、前記円筒空間内の
半径方向に傾斜磁場分布を供給する傾斜磁場発生手段と
,前記傾斜磁場発生手段を前記円筒空間内の所定の位置
に固定する支持体とを備えて成る核磁気共鳴装置におい
て、前記円筒空間内に傾斜磁場発生手段配置空間を遮断
するように設置された,外部からの信号により変形を抑
制することができる防音板(2は防音シート)と,音波
あるいは振動検出手段からの信号によりそれに応じた信
号を前記防音板又は防音シートに出力する制御装置を設
けたものである。An object of the present invention is to provide a nuclear magnetic resonance apparatus that suppresses vibrations and noise generated by gradient magnetic field coils and improves the examination condition of the examinee without giving the examinee a feeling of pressure. [Means for Solving the Problems] In order to achieve the above object, the present invention provides strong magnetic field generating means for supplying a uniform high magnetic field to a cylindrical space, and supplying a gradient magnetic field distribution in the radial direction within the cylindrical space. In a nuclear magnetic resonance apparatus comprising a gradient magnetic field generating means and a support for fixing the gradient magnetic field generating means at a predetermined position within the cylindrical space, a space for arranging the gradient magnetic field generating means is blocked in the cylindrical space. A soundproof board (2 is a soundproof sheet) installed in such a manner that the deformation can be suppressed by an external signal, and a corresponding signal is output to the soundproof board or soundproof sheet by a signal from a sound wave or vibration detection means. It is equipped with a control device to
また、音波あるいは振動検出手段として,前記防音板又
は防音シートが兼ねたものである.あるいは,前記円筒
空間内に音波を感知し、その信号を出力する音波あるい
は振動検出手段を設けたものである.
〔作用〕
本発明において、制御装置は、防音板又は防音シートが
変形しないように動作する。それによって防音板は、本
装置運転時に傾斜磁場コイルの振動により発生する騒音
を被検査者の位置する空間へ伝達させないように動作す
る.従って、被検査者が聴音する騒音が抑制され、被検
査者の不快感、不安感が低減される.
また、音波,あるいは、振動検出手段は、音波あるいは
振動を感知し、その信号を制御装置に出力するように動
作する。The soundproof board or sheet also serves as a means for detecting sound waves or vibrations. Alternatively, a sound wave or vibration detection means is provided within the cylindrical space to detect sound waves and output the signals. [Function] In the present invention, the control device operates so that the soundproof board or the soundproof sheet is not deformed. As a result, the soundproof plate operates to prevent the noise generated by the vibration of the gradient magnetic field coil from being transmitted to the space where the test subject is located when the device is in operation. Therefore, the noise that the test subject hears is suppressed, and the test subject's discomfort and anxiety are reduced. Further, the sound wave or vibration detection means operates to sense sound waves or vibrations and output the signal to the control device.
以下,本発明の実施例を図面に基づいて説明する。 Embodiments of the present invention will be described below based on the drawings.
第1図は本発明の第一の実施例に係る核磁気共鳴装置の
構造を示す側断面図である.第2図は第1図中の傾斜磁
場コイル系の断面図である.筒状の静磁場発生装置1に
よって中央部空間のボア2内に軸方向の0.5 〜4テ
スラの静磁場が発生する.
ボア2内には、静磁場方向2に対して,それぞれX方向
,y方向,2方向に傾斜磁場を発生する傾斜磁場コイル
系が配置されている.傾斜磁場コイル11.12は締結
金具により締結し、一体化端を固定したボビンエ5で支
持される.ここで頻雑さを避けるため、X及びy方向の
傾斜磁場コイルのみを示している.
鞍形の傾斜磁場コイル11及び12に傾斜磁場発生用の
パルス電流を流す場合、コイル円周部に作用する電磁力
は,フレミングの左手の法則に従い、静磁場方向が第王
図中左から右方向にある時,左端上側コイル円周部には
半径方向外向に,同下側のコイル円周部には半径方向軸
中心向きに作用する.また、コイル11及び12の左側
中央部の円周部には電流が逆向きに流れるので、これと
逆向きの荷重が作用する。この荷重は、傾斜磁場コイル
1l、及び、12が強固に連結され,剛性が大きくなっ
ていること、且つ、多数個の弾性体14によって吸収さ
れることから低減できる。FIG. 1 is a side sectional view showing the structure of a nuclear magnetic resonance apparatus according to a first embodiment of the present invention. Figure 2 is a cross-sectional view of the gradient magnetic field coil system in Figure 1. A cylindrical static magnetic field generator 1 generates a static magnetic field of 0.5 to 4 Tesla in the axial direction within the bore 2 of the central space. A gradient magnetic field coil system is arranged in the bore 2 to generate gradient magnetic fields in the X direction, the y direction, and two directions, respectively, with respect to the static magnetic field direction 2. The gradient magnetic field coils 11 and 12 are fastened with fastening metal fittings and supported by a bobbin 5 whose integrated end is fixed. Here, to avoid complexity, only the gradient coils in the X and Y directions are shown. When a pulse current for generating a gradient magnetic field is passed through the saddle-shaped gradient magnetic field coils 11 and 12, the electromagnetic force acting on the circumference of the coil follows Fleming's left-hand rule, and the direction of the static magnetic field is from left to right in the diagram. At some point, the force acts radially outward on the upper left coil circumference, and acts radially toward the center of the axis on the lower coil circumference. Furthermore, since current flows in the opposite direction to the left-side center circumferential portion of the coils 11 and 12, a load in the opposite direction acts on the coils 11 and 12. This load can be reduced because the gradient magnetic field coils 1l and 12 are firmly connected and have high rigidity, and because it is absorbed by the large number of elastic bodies 14.
しかし、この場合に吸収できなかった荷重はボビン15
を振動し騒音を発生する.この騒音は、ボビン15の内
外周面に貼付されているウレタン、グラスウール,モル
トブレーンなどの吸音材13によって発生を抑制されて
いるが、被検査者が聴音する騒音の吸音は不十分である
.そこで本発明では、被検査者の位置する円筒空間内に
,傾斜磁場コイル系より一定空間l6をおいて傾斜磁場
コイル系配置空間と被検査者の位置する空間を完全に分
離,遮断するように、外部からの信号により変形を抑制
することができる防音板、又は,防音シ一ト5を設置す
る。以後,防音板又は防音シートを防音部材と呼ぶ。こ
の時、静磁場発生装置の外に、漏えい磁場空間域を小さ
く押えるために設けられている鉄製の磁気シールド体6
に固定されることにより分離・遮断が成されている。However, in this case, the load that could not be absorbed is the bobbin 15.
vibrates and generates noise. Although the generation of this noise is suppressed by the sound absorbing material 13 such as urethane, glass wool, maltbrane, etc. attached to the inner and outer peripheral surfaces of the bobbin 15, the sound absorption of the noise heard by the testee is insufficient. Therefore, in the present invention, a certain space l6 is provided from the gradient magnetic field coil system in the cylindrical space where the test subject is located, so that the gradient magnetic field coil system placement space and the space where the test subject is located are completely separated and cut off. , a soundproof board or soundproof sheet 5 that can suppress deformation due to external signals is installed. Hereinafter, the soundproofing board or soundproofing sheet will be referred to as a soundproofing member. At this time, an iron magnetic shield 6 is installed outside the static magnetic field generator to suppress the leakage magnetic field space.
Separation and isolation are accomplished by fixing the
ここで防音部材5は、制御装置8からの・制御信号10
により変形を抑制することができる機能、且つ,防音部
材自体の一部、あるいは、全体の変形を感知する機能を
もっており,例えば、電圧を印加することにより面内方
向に伸縮する圧電フイルムを複数枚貼り合わせた構造の
ものであり、面外方向の変形を扱えるものである.
本構造の動作について以下に述べる。ボビン15の振動
より発生した騒音の音波により防音板5の一部,あるい
は、全体が面外方向に変形させられようとした場合、制
御装置8からの適切な制御人力10により防音部材5の
一部,あるいは,全体をその変形方向とは逆方向に変形
させようとする.これにより、防音板の面外方向への変
形は抑制され,被検査者の位置する空間への騒音の伝達
が抑制される.よって被検査者が聴音する騒音は低減さ
れる.
本実施例では、防音部材5は前述したように、防音部材
5自体の一部あるいは全体の変形を感知する機能をもっ
ており、制御装置8との結合により閉ループフィードバ
ック制御系を構成している。Here, the soundproofing member 5 receives a control signal 10 from the control device 8.
It has the function of suppressing deformation due to the soundproofing member itself, and the function of sensing the deformation of a part of the soundproofing member itself or the entirety. It has a bonded structure and can handle deformation in the out-of-plane direction. The operation of this structure will be described below. If a part or the whole of the soundproof plate 5 is to be deformed in an out-of-plane direction due to the sound waves of the noise generated by the vibration of the bobbin 15, the soundproof member 5 can be partially deformed by an appropriate control force 10 from the control device 8. Attempts to deform a part or the whole in the opposite direction to its deformation direction. As a result, deformation of the soundproof board in the out-of-plane direction is suppressed, and the transmission of noise to the space where the test subject is located is suppressed. Therefore, the noise that the test subject hears is reduced. In this embodiment, as described above, the soundproofing member 5 has a function of sensing deformation of a part or the whole of the soundproofing member 5 itself, and is combined with the control device 8 to form a closed loop feedback control system.
第3図は本実施例に適用する制御装置8のブロック図で
ある.
本実施例における制御装置8は、増幅器8a,ゲイン調
節器8b,電圧発生器8c,電圧増幅器8dにより構成
されている.動作は、まず防音部材の変形に伴う防音部
材からの微少な検出信号9が増幅器8aにより増幅され
る.次に,ゲイン調節器8bによりその検出信号に適切
な制御ゲインが乗じられ、それに応じた電圧が電圧発生
器8Cによって発生される.さらに、それは電圧増幅器
8dにより増幅され最終的に制御信号として防音部材に
印加され、防音部材5の面外変形を制御する。FIG. 3 is a block diagram of the control device 8 applied to this embodiment. The control device 8 in this embodiment includes an amplifier 8a, a gain adjuster 8b, a voltage generator 8c, and a voltage amplifier 8d. In operation, first, a minute detection signal 9 from the soundproofing member due to the deformation of the soundproofing member is amplified by the amplifier 8a. Next, the detection signal is multiplied by an appropriate control gain by the gain adjuster 8b, and a corresponding voltage is generated by the voltage generator 8C. Further, it is amplified by the voltage amplifier 8d and finally applied to the soundproofing member as a control signal to control the out-of-plane deformation of the soundproofing member 5.
次に,第4図を参照して第二の実施例について説明する
。第4図は,本実施例に係る核磁気共鳴装置の構造を示
す部分側断面図である.本実施例は、第一の実施例にお
いて、防音部材5がそれ自体の変形を感知する機能をも
っておらず、円筒形内に、騒音の音波を感知する機能を
もつ少なくともl個あるいは複数個の例えば音響センサ
17a,17bを設置した場合であり、検出信号9a,
9bが制御装置8に入力される。本実施例,音波、ある
いは、振動検出手段が第一の実施例と異るだけで、音波
あるいは振動検出後の動作及び効果は第一の実施例と同
様となる.次に、第5図を参照して第三の実施例につい
て説明する.第5図は、本実施例に係る核磁気共鳴装置
の構造を示す部分側断面図である。Next, a second embodiment will be described with reference to FIG. FIG. 4 is a partial side sectional view showing the structure of the nuclear magnetic resonance apparatus according to this embodiment. This embodiment differs from the first embodiment in that the soundproofing member 5 does not have the function of sensing its own deformation, but has at least l or a plurality of e.g. This is a case where acoustic sensors 17a and 17b are installed, and detection signals 9a,
9b is input to the control device 8. This embodiment differs from the first embodiment only in the sound wave or vibration detection means, but the operation and effects after sound wave or vibration detection are the same as in the first embodiment. Next, a third embodiment will be explained with reference to FIG. FIG. 5 is a partial side sectional view showing the structure of the nuclear magnetic resonance apparatus according to this embodiment.
本実施例も第二の実施例と同様に、防音部材5がそれ自
体の変形を感知する機能をもっていない場合である.従
って音波,あるいは、振動検出手段として,防音波5の
変形を感知する機能をもつ少なくとも一個、あるいは、
複数個の例えば振動センサ18を防音板5に設置した.
本実施例も、音波,あるいは,振動検出後の動作及び効
果は第一の実施例と同様となる。Similar to the second embodiment, this embodiment is also a case in which the soundproofing member 5 does not have the function of sensing its own deformation. Therefore, as a sound wave or vibration detection means, at least one piece having a function of sensing the deformation of the sound wave proofing 5, or
For example, a plurality of vibration sensors 18 are installed on the soundproof board 5.
In this embodiment as well, the operation and effects after sound waves or vibrations are detected are similar to those in the first embodiment.
本発明によれば、検査時の傾斜磁場コイル振動により発
生する騒音が被検査者の位置する空間へ伝達するのを抑
制することができる。且つ、抑制を行なった際における
核磁気共鳴装置の大型化がないために被検査者は、圧迫
感,不快感を持たずに検査を受けることができる。According to the present invention, it is possible to suppress the noise generated by the vibration of the gradient magnetic field coil during the test from being transmitted to the space where the test subject is located. In addition, since the nuclear magnetic resonance apparatus does not increase in size when the suppression is performed, the examinee can undergo the examination without feeling pressured or uncomfortable.
第I図は本発明の一実施例に係る核磁気共鳴装置の内部
構造物の部分側断面図、第2図は第1図実施例に適用す
る傾斜磁場コイル系の詳細を示す要部断面図,第3図は
本発明実施例に適用する制御装置のブロック図、第4図
は本発明の第二の実施例に係る核磁気共鳴装置の内部構
造物の部分側断面図、第5図は本発明の第三の実施例に
係る核磁気共鳴装置の内部構造物の部分側断面図である
。
5・・・防音板、8・・・制御装置、9,9a,9b・
・・検出信号、10・・・制御信号、17a,17b・
・・音響目
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qa.yb−rヒ定二dニイ言うシ
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t2 ・−My 省h x−.zFig. I is a partial side sectional view of the internal structure of a nuclear magnetic resonance apparatus according to an embodiment of the present invention, and Fig. 2 is a sectional view of main parts showing details of the gradient magnetic field coil system applied to the embodiment of Fig. 1. , FIG. 3 is a block diagram of a control device applied to an embodiment of the present invention, FIG. 4 is a partial side sectional view of the internal structure of a nuclear magnetic resonance apparatus according to a second embodiment of the present invention, and FIG. 5 is a block diagram of a control device applied to an embodiment of the present invention. FIG. 7 is a partial side sectional view of the internal structure of a nuclear magnetic resonance apparatus according to a third embodiment of the present invention. 5... Soundproof board, 8... Control device, 9, 9a, 9b.
...Detection signal, 10...Control signal, 17a, 17b.
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Claims (1)
と、前記円筒空間内の半径方向に傾斜磁場分布を供給す
る傾斜磁場発生手段と、前記傾斜磁場発生手段を前記円
筒空間内の所定の位置に固定する支持体とを備えて成る
核磁気共鳴装置において、 前記円筒空間内に前記傾斜磁場発生手段の配置空間を遮
断するように設置された外部からの信号により変形を抑
制することができる防音板と、音波あるいは振動検出手
段からの信号によりそれに応じた信号を前記防音板に出
力する制御装置とを設けたことを特徴とする核磁気共鳴
装置。 2、請求項1において、前記防音板が音波あるいは振動
検出手段を兼ねた核磁気共鳴装置。 3、請求項1において、前記円筒空間内に音波を感知し
、その信号を出力する音波あるいは振動検出手段を設け
た核磁気共鳴装置。[Scope of Claims] 1. Strong magnetic field generating means for supplying a uniform high magnetic field to a cylindrical space, gradient magnetic field generating means for supplying a gradient magnetic field distribution in the radial direction within the cylindrical space, and the gradient magnetic field generating means A nuclear magnetic resonance apparatus comprising: a support fixed at a predetermined position within the cylindrical space; A nuclear magnetic resonance apparatus comprising: a soundproof plate that can suppress deformation; and a control device that outputs a signal to the soundproof plate according to a signal from a sound wave or vibration detection means. 2. The nuclear magnetic resonance apparatus according to claim 1, wherein the soundproof plate also serves as a sound wave or vibration detection means. 3. The nuclear magnetic resonance apparatus according to claim 1, further comprising sound wave or vibration detection means for detecting sound waves in the cylindrical space and outputting the signals.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1302163A JP2791150B2 (en) | 1989-11-22 | 1989-11-22 | Nuclear magnetic resonance equipment |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP1302163A JP2791150B2 (en) | 1989-11-22 | 1989-11-22 | Nuclear magnetic resonance equipment |
Publications (2)
Publication Number | Publication Date |
---|---|
JPH03162831A true JPH03162831A (en) | 1991-07-12 |
JP2791150B2 JP2791150B2 (en) | 1998-08-27 |
Family
ID=17905681
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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JP1302163A Expired - Fee Related JP2791150B2 (en) | 1989-11-22 | 1989-11-22 | Nuclear magnetic resonance equipment |
Country Status (1)
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JP (1) | JP2791150B2 (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013125602A1 (en) * | 2012-02-22 | 2013-08-29 | 株式会社 東芝 | X-ray ct device |
-
1989
- 1989-11-22 JP JP1302163A patent/JP2791150B2/en not_active Expired - Fee Related
Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
WO2013125602A1 (en) * | 2012-02-22 | 2013-08-29 | 株式会社 東芝 | X-ray ct device |
CN103796591A (en) * | 2012-02-22 | 2014-05-14 | 株式会社东芝 | X-ray ct device |
US9414793B2 (en) | 2012-02-22 | 2016-08-16 | Toshiba Medical Systems Corporation | X-ray CT system |
Also Published As
Publication number | Publication date |
---|---|
JP2791150B2 (en) | 1998-08-27 |
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