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公开(公告)号：US5631616A
公开(公告)日：1997-05-20
申请号：US417037
申请日：1995-04-05
申请人： Kimiharu Ohta , Shigeo Hashimoto , Masahiro Yuki , Hideya Sakurai
发明人： Kimiharu Ohta , Shigeo Hashimoto , Masahiro Yuki , Hideya Sakurai
IPC分类号： A61B5/055 , G01R33/383 , H01F7/02 , H01F1/00
CPC分类号： G01R33/383 , H01F7/0278
摘要： A magnetic field generating device for use in MRI having a pair of pole pieces opposed at a space to each other and generating a magnetic field in the space, wherein the pole piece has a laminate structure in which a soft ferrite and a magnetic material base are disposed from the side of the space, and a layer of small magnetic permeability and high electric resistance is interposed between the soft ferrite and the magnetic material base. The soft ferrite may be lamination of the soft ferrite and silicon steel sheets. High speed image pick-up at high sensitivity and sharpness is enabled by reducing the eddy current and the remanent magnetism generated in the pole piece by the gradient magnetic field coils.
摘要翻译： 一种用于MRI的磁场产生装置，具有一对彼此相对的空间的极片，并在该空间中产生磁场，其中极片具有层叠结构，其中软铁氧体和磁性材料基底为 从该空间的一侧配置，并且在软铁氧体和磁性体基体之间插入一层小的磁导率和高的电阻。 软铁氧体可以是软铁氧体和硅钢板的层压。 通过梯度磁场线圈减少磁极中产生的涡流和剩磁，可以实现高灵敏度和清晰度的高速摄像。
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公开(公告)号：USRE35565E
公开(公告)日：1997-07-22
申请号：US267515
申请日：1994-06-29
申请人： Hideya Sakurai , Junji Uzuki , Hikotaka Takeshima , Shigeru Sato
发明人： Hideya Sakurai , Junji Uzuki , Hikotaka Takeshima , Shigeru Sato
IPC分类号： G01R33/383 , H01F7/02 , G01V3/00
CPC分类号： G01R33/383 , H01F7/0278
摘要： A magnetic field generating apparatus for a magnetic resonance imaging (MRI) apparatus, including soft ferrite disposed adjacently to a gradient magnetic field coil which is disposed in a gap and serves to form a static magnetic field. The soft ferrite has saturated magnetic flux density (Rs) more than 0.4 T, coersive force (He) less than 50 A/m, and specific resistance .rho. more than 10.sup.-5 .OMEGA..multidot.cm. The magnetic field generating apparatus thus constructed has a magnetic circuit arrangement that a pair of permanent magnetic bodies which are disposed so as to confront each other and define the gap are magnetically connected through a yoke, and pole pieces are fixedly secured to the surfaces of the respective permanent magnetic bodies facing the gap, thereby generating the magnetic field in the gap.
摘要翻译： 一种用于磁共振成像（MRI）装置的磁场产生装置，包括设置在间隙中并用于形成静磁场的梯度磁场线圈相邻的软铁氧体。 软铁氧体的饱和磁通密度（Rs）大于0.4T，凝聚力（He）小于50A / m，电阻rho大于10-5OEGEGA×cm。 这样构成的磁场产生装置具有：磁路装置，通过磁轭将配置成彼此面对并限定间隙的一对永久磁体固定地固定在 各个永久磁体面对间隙，从而在间隙中产生磁场。
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公开(公告)号：US5283544A
公开(公告)日：1994-02-01
申请号：US766520
申请日：1991-09-27
申请人： Hideya Sakurai , Masaaki Aoki
发明人： Hideya Sakurai , Masaaki Aoki
IPC分类号： G01R33/383 , H01F7/02 , H01F1/00
CPC分类号： H01F7/0278 , G01R33/383
摘要： A magnetic field generating device used for MRI includes a pair of magnetic pole pieces to each other to provide a gap therebetween and generate a magnetic field in the gap, the magnetic pole pieces being formed by laminating and integrating a plurality of non-oriented silicon steel sheets. By using laminated non-oriented silicon sheets the eddy current generated in the magnetic pole pieces caused by the application of GC pulses can be reduced and phenomenon of the residual magnetism can also be reduced.
摘要翻译： 用于MRI的磁场产生装置包括一对磁极片，以在它们之间提供间隙，并在间隙中产生磁场，磁极片通过将多个非取向硅钢 床单。 通过使用层叠的无取向硅片，可以减少由施加GC脉冲而引起的在磁极片中产生的涡流，并且还可以减少残余磁性的现象。
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公开(公告)号：US5229723A
公开(公告)日：1993-07-20
申请号：US550081
申请日：1990-07-09
申请人： Hideya Sakurai , Masaaki Aoki , Youichi Ohnishi
发明人： Hideya Sakurai , Masaaki Aoki , Youichi Ohnishi
IPC分类号： A61B5/055 , G01R33/38 , G01R33/383 , G01R33/3873 , H01F7/02
CPC分类号： G01R33/3873 , G01R33/383
摘要： Disclosed is an MRI-dedicated magnetic field generating device for generating magnetic fields within an air gap, including: a pair of permanent magnet assemblies opposite to each other to form an air gap therebetween; yokes for magnetically linking the permanent magnet assemblies; and magnetic pole pieces fixed to air-gap-confronting surfaces thereof. Based on this construction, intensities of the magnetic fields are increased by disposing a plurality of magnetic material segments on the same circle or a concentric circle on the confronting surface thereof or decreased by disposing a plurality of permanent magnet segments having a magnetizing direction opposite to that of the permanent magnet assemblies on the same circle or the concentric circle on the confronting surface thereof; or alternatively both the magnetic material segments and the permanent magnet segments are disposed on the same circle or the concentric circle.
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公开(公告)号：US4818966A
公开(公告)日：1989-04-04
申请号：US174172
申请日：1988-03-28
IPC分类号： A61B5/055 , G01R33/383 , H01F7/02 , H01F3/04
CPC分类号： H01F7/0278 , G01R33/383
摘要： A magnetic field-generating device includes a pair of permanent magnet components disposed in such a manner as to face each other with a gap formed therebetween, a yoke for magnetically coupling the pair of permanent magnet components, and pole pieces which are each fixed to a surface of a corresponding permanent magnet component that faces the gap. The magnetic field generating device is adpated to generate a magnetic field in the gap. Each of the pole pieces is made of a laminate of magnetic plates which laminated in a direction substantially perpendicular to the sides of the solid care portion.
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公开(公告)号：US4777464A
公开(公告)日：1988-10-11
申请号：US101365
申请日：1987-09-25
IPC分类号： G01R33/38 , G01R33/383 , H01F7/02
CPC分类号： H01F7/0278 , G01R33/3806 , G01R33/383
摘要： A magnetic field generating device for the NMR-CT comprises a pair of opposing permanent magnet segments magnetically coupled by a yoke which define therebetween an air gap where a magnetic field is created. Each segment has a pole piece attached to its gap-facing surface. Each segment is composed of a ferrite magnet and a rare earth magnet, one of the two magnets being disposed in the central portion of the segment and the other disposed around the one magnet. The thickness of the ferrite magnet in the direction of attaching it to the yoke is larger than that of the rare earth magnet.
摘要翻译： 用于NMR-CT的磁场产生装置包括一对相对的永磁体段，磁轭通过磁轭磁耦合，在其间限定产生磁场的气隙。 每个段具有连接到其面向间隙的表面的极片。 每个段由铁氧体磁体和稀土磁体组成，两个磁体中的一个设置在该段的中心部分，另一个设置在一个磁体周围。 铁氧体磁铁的附着方向的厚度大于稀土类磁铁的厚度。
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公开(公告)号：US4672346A
公开(公告)日：1987-06-09
申请号：US719820
申请日：1985-04-04
IPC分类号： B29C67/20 , C08J5/18 , G01R33/383 , H01F7/02 , H01F7/00
CPC分类号： C08J5/18 , B29C67/20 , G01R33/383 , H01F7/0278 , C08J2323/02
摘要： A magnetic field generating device for a nuclear magnetic resonance-computerized tomography comprising a pair of permanent magnets magnetized in the same direction with different-polarity poles opposing mutually to define an air gap, whose maximum energy product, (BH).sub.max, is not less than 30 MGOe (240 KJ/m.sup.3), on each of the opposing faces of the permanent magnets a magnetic pole segment being provided which has an annular projection and, as occasion demands, at least one central convex projection inside the annular projection, and the permanent magnets being coupled magnetically by a yoke to generate a magnetic field within the air gap.The present device is able to create a uniform and stable magnetic field, in spite of its small-sized body.
摘要翻译： 一种用于核磁共振计算机断层摄影的磁场产生装置，包括一对永磁体，该永久磁体在与相互相对的相反极性磁极相同的方向上磁化，以限定气隙，其最大能量乘积（BH）max不小于 在超过30MGOe（240KJ / m3）的情况下，在永磁体的每个相对面上设置有磁极段，其具有环形突起，并且根据需要，在环形突起内部具有至少一个中心凸起突起，并且 永磁体由磁轭磁耦合以在气隙内产生磁场。 本设备能够创建均匀且稳定的磁场，尽管其体积小。
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公开(公告)号：US5252924A
公开(公告)日：1993-10-12
申请号：US793466
申请日：1991-11-18
申请人： Hideya Sakurai , Junji Uzuki , Hirotaka Takeshima , Shigeru Sato
发明人： Hideya Sakurai , Junji Uzuki , Hirotaka Takeshima , Shigeru Sato
IPC分类号： G01R33/383 , H01F7/02 , G01V3/00
CPC分类号： H01F7/0278 , G01R33/383
摘要： A magnetic field generating apparatus for a magnetic resonance imaging (MRI) apparatus, including soft ferrite disposed adjacently to a gradient magnetic field coil which is disposed in a gap and serves to form a static magnetic field. The soft ferrite has saturated magnetic flux density (Rs) more than 0.4 T, coersive force (He) less than 50 A/m, and specific resistance .rho. more than 10.sup.-5 .OMEGA..multidot.cm. The magnetic field generating apparatus thus constructed has a magnetic circuit arrangement that a pair of permanent magnetic bodies which are disposed so as to confront each other and define the gap are magnetically connected through a yoke, and pole pieces are fixedly secured to the surfaces of the respective permanent magnetic bodies facing the gap, thereby generating the magnetic field in the gap.
摘要翻译： 一种用于磁共振成像（MRI）装置的磁场产生装置，包括设置在间隙中并用于形成静磁场的梯度磁场线圈相邻的软铁氧体。 软铁氧体的饱和磁通密度（Rs）大于0.4T，凝聚力（He）小于50A / m，电阻rho大于10-5OEGEGA×cm。 这样构成的磁场产生装置具有：磁路装置，通过磁轭将配置成彼此面对并限定间隙的一对永久磁体固定地固定在 各个永久磁体面对间隙，从而在间隙中产生磁场。
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公开(公告)号：US4679022A
公开(公告)日：1987-07-07
申请号：US909327
申请日：1986-09-19
IPC分类号： G01R33/383 , H01F7/02
CPC分类号： G01R33/383 , H01F7/0278
摘要： A magnetic field generating device for nuclear magnetic resonance-computerized tomography of the type wherein permanent magnet assemblies of a pair opposing mutually to define an air gap therebetween are magnetically coupled together by yoke means to create a magnetic field within the air gap is provided, which is characterized in that each permanent magnet assembly comprises a flat plate-like central permanent magnet and peripheral permanent magnets arranged around the central permanent magnet and inclined toward the inside of the air gap, the magnetic pole surface of each permanent magnet assembly forms a curved concave face with respect to the air gap, and each permanent magnet is magnetized in the direction perpendicular to the corresponding magnetic pole surface, whereby the leakage flux is reduced and the magnetic efficiency is enhanced, thus, reduction of the device dimension and weight can be achieved.
摘要翻译： 一种用于核磁共振计算机断层摄影的磁场产生装置，其中一对相对的互相定义气隙的永磁体组件通过轭装置磁耦合在一起，以在气隙内产生磁场，其中 其特征在于，每个永磁体组件包括平板状中心永磁体和围绕中心永磁体布置并且朝向空气间隙的内侧倾斜的外围永磁体，每个永磁体组件的磁极表面形成弯曲的凹部 并且每个永磁体在垂直于相应的磁极表面的方向上被磁化，从而减小漏磁通并提高磁效率，从而可以实现器件尺寸和重量的减小 。
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