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81. 发明专利

JPH0722577B2 失效
公开(公告)号：JPH0722577B2
公开(公告)日：1995-03-15
申请号：JP28876988
申请日：1988-11-17
IPC分类号： E06B5/00 , A61B5/055 , E06B5/18 , G01R33/28 , G01R33/42 , G01R33/421 , H05K9/00

82. 发明专利

JPH0672937B2 失效
公开(公告)号：JPH0672937B2
公开(公告)日：1994-09-14
申请号：JP31472288
申请日：1988-12-13
IPC分类号： E06B5/00 , A61B5/055 , E06B5/18 , G01R33/28 , G01R33/42 , G01R33/421 , G12B17/02 , H05K9/00

83. 发明专利

JPH0622926A MAGNETIC RESONANCE IMAGE PICK-UP AND DEVICE THEREFOR 失效
公开(公告)号：JPH0622926A
公开(公告)日：1994-02-01
申请号：JP5183293
申请日：1993-03-12
申请人： TOSHIBA CORP
发明人： KUHARA SHIGEHIDE , SATO KOZO , KANAYAMA SHOICHI
IPC分类号： A61B5/055 , G01R33/38 , G01R33/389 , G01R33/42 , G01R33/421
摘要： PURPOSE:To prevent the generation of the stimulation of nerve by reducing the eddy current induced in a living body outside an image pick-up range, by installing a shield member for magnetically shielding the part of a body to be inspected in the vicinity of the point where the gradient magnetic field or the cross magnetic field which is simultaneously generated with the gradient magnetic field becomes max., outside the image pick-up region. CONSTITUTION:When the strong gradient magnetic field used in a superhigh speed MRI(magnetic resonance image method) is represented by Gx, if, in case of the breast part as imaging object, the absolute value of the magnetic field of the magnetic field intensity zGx of the head part of the (x) component as the cross magnetic field component is larger than that of the magnetic field intensity xGx on the breast part side where the (z) component necessary for imaging becomes max., and dB/dt is large. Accordingly, the head part and the waist part are surrounded by the electric conductive material I. Accordingly, the magnetic field intensity, i.e., dB/dt of the inside surrounded by the electric conductive material I reduces because of the counter magnetic field due to the eddy currents 2 and 3 generated in the electric conductive material I. Accordingly, the eddy current density induced inside a living body can be reduced less than the min. level of the nerve stimulus.

84. 发明专利

JPH0515512A MAGNETIC RESONANCE INSPECTION DEVICE 失效
公开(公告)号：JPH0515512A
公开(公告)日：1993-01-26
申请号：JP17120591
申请日：1991-07-11
申请人： HITACHI LTD
发明人： TSUDA MUNETAKA , YABUSAKI YUKIO
IPC分类号： A61B5/055 , G01R33/42 , G01R33/421 , G01R33/422
摘要： PURPOSE:To improve the quality of picture and power source efficiency with a smaller coil by arranging an inclined magnetic field coil and a high frequency shielding body outside a high frequency coil to make a support of the inclined magnetic field coil transit a high frequency magnetic field. CONSTITUTION:A Faraday shield 21 as high frequency shielding body is mounted on an internal surface of an inner cylinder member of a superconductive magnet 2, for example, by sticking to be kept at a ground potential. An inclined magnetic field coil support 9 is set concentrically into an inertial chamber of the Faraday shield 21. For example, a plurality of capacitor elements 22 with a capacitance value of 0.1muF are sustained between inclined magnetic field coils 3, 4 and 5 and the Faraday shield 21. Moreover, a high frequency coil 6 is incorporated concentrically into an internal space of the inclined magnetic field coil support 9. A high frequency magnetic flux generated when a high frequency power is applied to the high frequency oil 6 is as shown by the broken line. The high frequency magnetic field is transmitted through the inclined magnetic field coil support 9 thereby forming a flux distribution almost the same as that when there is no inclined magnetic field coil.

85. 发明专利

JPH03295538A MAGNETIC RESONANCE IMAGING DEVICE 失效
公开(公告)号：JPH03295538A
公开(公告)日：1991-12-26
申请号：JP9515790
申请日：1990-04-12
申请人： TOSHIBA CORP , TOSHIBA MEDICAL ENG
发明人： MAKITA JUNICHI , SEGAWA TORU
IPC分类号： G01R33/421 , A61B5/055 , G01R33/42
摘要： PURPOSE:To reduce the burden of a body to be examined and to decrease the fixed time of the body to be examined by installing an RF shield member having flexibility to a non-photographing part positioned in the vicinity of a photographing part of the body to be examined. CONSTITUTION:By allowing a body P to be examined, placed in a magnet device to generate a magnetic resonance phenomenon, a magnetic resonance image of this body P to be examined is obtained. In this case, an RF shield member 2 having flexibility is installed in a non-photographing part positioned in the vicinity of a photographing part (for instance, a hand) P of the body P to be examined. By this RF shield member 2, an RF signal to the non- photographing part is shielded, and generation of a magnetic resonance signal is prevented. Also, since this RF shield member 2 has flexibility, it can be installed easily in the non-photographing part positioned in the vicinity of the photographing part of the body P to be examined.

86. 发明专利

JPH03210238A MRI DEVICE 失效
公开(公告)号：JPH03210238A
公开(公告)日：1991-09-13
申请号：JP336390
申请日：1990-01-12
申请人： TOSHIBA CORP
发明人： YOKOI MOTOTAKA
IPC分类号： G01R33/421 , A61B5/055 , G01R33/42
摘要： PURPOSE:To form a desired gradient magnetic field by constituting this device so that the ratio of a current flowing through a gradient magnetic field coil and a current flowing through a shielding coil becomes constant with a current control means. CONSTITUTION:The device is provided with a static magnetic field generating means 4 which is arranged on the outside of an opening part 12 in which a living body is arranged and generates a uniform static magnetic field to the inside of the opening part 12, and a gradient magnetic field coil Cg which is arranged on the inside of the means 4 and forms a desired gradient magnetic field superposed on the uniform static magnetic field. In such a state, a shielding coil Cc which is arranged between the coil Cg and the means 4 and connected in series to the coil Cg forms a magnetic field which can offset a magnetic field formed on the outside of the coil Cg. Also, by one piece of gradient magnetic field power source 14, a current is supplied to the coils Cg, Cc. Moreover, current control means 30, 40 connected in parallel to the coil Cc allow a control current to flow to the coil Cc so that the ratio of currents flowing through the coils Cg, Cc becomes constant, based on an output current signal from the power source 14 and a current flowing through itself.

87. 发明专利

JPH0387688A SUPERCONDUCTIVE MAGNETIC SHIELD BODY AND ITS MANUFACTURE 失效
公开(公告)号：JPH0387688A
公开(公告)日：1991-04-12
申请号：JP8955290
申请日：1990-04-04
申请人： NGK INSULATORS LTD
发明人： WATANABE KEIICHIRO , YOSHIDA HITOSHI , SAKAI HITOSHI , OKI SHUICHIRO
IPC分类号： G12B17/02 , A61B5/055 , G01R33/20 , G01R33/42 , G01R33/421 , H01L39/00 , H05K9/00
摘要： PURPOSE:To appropriately shield the magnetism from a magnetic source by constituting the magnetic source to be shielded, of a three-layer structure of an outside metallic cylinder, a superconductive layer and an inside metallic cylinder from the magnetic source side. CONSTITUTION:An outside cylinder 10 consists of various metals of, for instance, 1mm wall thickness, 100mm inside diameter and 200mm length, and an inside cylinder 11 consists of various metals of, for instance, 1mm wall thickness, 80 - 98mm outside diameter and 200mm length. By inserting the cylinder 11 into the inside of this cylinder 10, its one side end part is welded along the periphery, and also, the inside of a clearance between this cylinder 10 and the cylinder 11 is filled with powder 12 consisting of a ceramics superconductor in which a main component of a crystal phase is, for instance, YBa2Cu3O7-Y, etc., the remaining one side end part is welded along the cylinder, and thereafter, the deaeration is executed by a vacuum pump 14 from a deaeration port 13. Subsequentlly, the deaeration port 13 is sealed. Next, heat and hydrostatic pressure are applied by argon gas, and after sintering powder 12 by applying heat and pressure, it is cooled by liquid nitrogen.

88. 发明专利

JPH0318323B2 失效
公开(公告)号：JPH0318323B2
公开(公告)日：1991-03-12
申请号：JP9294487
申请日：1987-04-15
申请人： SIEMENS AG
发明人： HERUMUUTO FUORUSUTAA , HORUSUTO JIIBORUTO
IPC分类号： G01R33/20 , A61B5/055 , A61B10/00 , G01R33/38 , G01R33/42 , G01R33/421 , H01F7/20

89. 实用新型

JPH0245712U 失效
公开(公告)号：JPH0245712U
公开(公告)日：1990-03-29
申请号：JP10826689
申请日：1989-09-14
IPC分类号： G01R33/421 , A61B5/055 , G01R33/34 , G01R33/341 , G01R33/36 , A61B5/05 , G01N24/04 , G01R33/22 , G01R33/42

90. 发明专利

JPH0282943A MAGNETIC FIELD GENERATOR FOR MAGNETIC RESONANCE 失效
公开(公告)号：JPH0282943A
公开(公告)日：1990-03-23
申请号：JP23528188
申请日：1988-09-20
申请人： HITACHI LTD
发明人： MIYAJIMA TAKESHI , SHUDO TAKESHI , KURODA KUNISHIGE , TAKAHASHI TAKAO , SUZUKI SHOHEI
IPC分类号： G01R33/421 , A61B5/055 , G01R33/42
摘要： PURPOSE:To correct an inclined magnetic field and to miniaturize the title generator by providing a coil like closed circuit composed of the electric good conductor subjected to the inductive coupling with an inclined magnetic field coil between a static magnetic field coil and the inclined magnetic field coil and canceling the unnecessary leaked magnetic flux toward an ultralow temp. heat reflecting cylinder. CONSTITUTION:Canceling coil groups 18a, 18b are provided between a bore inner cylinder and an inclined magnetic field coil and connected so that a current direction becomes reverse by a pair of inclined magnetic field coils 17a, 17b generating the inclined magnetic field of the Z-term of the inclined magnetic field coil. Since an exciting current Igc has an AC component in rising and falling, the induced current Im in the direction opposite to the exciting current Igc flowing to a pair of the inclined magnetic field coils 17a, 17b flows to metal circular rings 18a, 18b. Since the induced current Im corresponds to the negating current in an active shield system inclined magnetic field coil system, the waveform of a distorted inclined magnetic field can be corrected.

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