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    Shielded room construction for containment of fringe magnetic fields
    1.
    发明公开
    Shielded room construction for containment of fringe magnetic fields 失效
    保护室建设保持弗朗斯磁场。

    公开(公告)号：EP0182284A2

    公开(公告)日：1986-05-28

    申请号：EP85114469.1

    申请日：1985-11-14

    申请人： GENERAL ELECTRIC COMPANY

    发明人： Vavrek, Robert Michael ,  Grigsby, Nancy Sue

    IPC分类号： G12B17/02 ,  G01R33/42

    CPC分类号： G12B17/02

    摘要： A shielded room for containment of magnetic fringe fields generated by a magnet which forms part of an NMR scanner system utilizes wall members having a thickness proportional to the amount of flux conducted. In the preferred embodiments, the shielded room can have one of rectangular, cylindrical, or polygonal geometries, for example. The walls (floors and ceilings) are constructed from staggered plates to have increased thickness where flux is greatest, and correspondingly decreased thickness where the flux is lowest. The shielded room can be, additionally, provided with end-cap elements in the walls perpendicular to the base of the magnet. Preferentially, the end-cap elements are angled away from the side wall members toward the center of the room to more closely follow the flux path.

    Gradient amplifier system for magnetic resonance imaging
    2.
    发明公开
    Gradient amplifier system for magnetic resonance imaging 失效
    用于磁共振成像的梯度放大器系统

    公开(公告)号：EP0454298A3

    公开(公告)日：1992-03-11

    申请号：EP91302248.9

    申请日：1991-03-15

    申请人： GENERAL ELECTRIC COMPANY

    发明人： Vavrek, Robert Michael ,  McFarland, Thomas George

    IPC分类号： G01R33/38

    CPC分类号： H03F3/2178 ,  G01R33/3852 ,  H03F2200/261

    摘要： A magnetic resonance imaging system uses a pool of amplifiers (42) to generate gradient signals. Each amplifier (42a,b,c,d) within the pool may be switched among any of the gradient axes, so as to efficiently allocate amplifier power among the gradients. In one embodiment, the amplifiers (42) of the pools are connected in stacks (19) by an input and output matrix comprised of mechanical switches driven in tandem by interlocked motors. The switches connect the outputs of the amplifiers in series. The input signal is "boot strapped" through the amplifier stack to provide proper signal level.

    Shielded room construction for containment of fringe magnetic fields
    3.
    发明公开
    Shielded room construction for containment of fringe magnetic fields 失效
    用于容纳FRINGE磁场的屏蔽室结构

    公开(公告)号：EP0182284A3

    公开(公告)日：1988-04-13

    申请号：EP85114469

    申请日：1985-11-14

    申请人： GENERAL ELECTRIC COMPANY

    发明人： Vavrek, Robert Michael ,  Grigsby, Nancy Sue

    IPC分类号： G12B17/02 ,  G01N24/06

    CPC分类号： G12B17/02

    摘要： A shielded room for containment of magnetic fringe fields generated by a magnet which forms part of an NMR scanner system utilizes wall members having a thickness proportional to the amount of flux conducted. In the preferred embodiments, the shielded room can have one of rectangular, cylindrical, or polygonal geometries, for example. The walls (floors and ceilings) are constructed from staggered plates to have increased thickness where flux is greatest, and correspondingly decreased thickness where the flux is lowest. The shielded room can be, additionally, provided with end-cap elements in the walls perpendicular to the base of the magnet. Preferentially, the end-cap elements are angled away from the side wall members toward the center of the room to more closely follow the flux path.

    Gradient amplifier system employing a combination of linear amplifiers and DC power sources
    4.
    发明公开
    Gradient amplifier system employing a combination of linear amplifiers and DC power sources 失效
    Gradientenverstärkermit einer Kombination von linearenVerstärkenund Gleichstromquellen。

    公开(公告)号：EP0562791A1

    公开(公告)日：1993-09-29

    申请号：EP93302137.0

    申请日：1993-03-22

    申请人： GENERAL ELECTRIC COMPANY

    发明人： McFarland, Thomas George ,  Vavrek, Robert Michael ,  Wirth, William Frederick

    IPC分类号： G01R33/38

    CPC分类号： G01R33/3852

    摘要： A gradient amplifier for use in magnetic resonance imaging equipment employs linear amplifiers in tandem with DC power supplies, the latter serving to provide increased power for rapid gradient switching and the former providing correction current to produce the desired continuous output. The DC power supplies are controlled open loop from the gradient signal used to designate the current in the gradient coil and the amplifiers are operated closed loop in response to a feedback signal from the gradient coil. The DC power supplies may comprise multiple DC units which may be combined to provide finer steps of control prior to correction by the linear amplifier. The units may be weighed in binary fashion to provide improved resolution. The DC power supply in a second embodiment may include storage capacitors that have their charge maintained by the amplifiers receiving a correction current derived from the peak charge on the capacitors.

    摘要翻译： 用于磁共振成像设备的梯度放大器采用与直流电源串联的线性放大器，后者用于为快速梯度切换提供增加的功率，前者提供校正电流以产生所需的连续输出。 直流电源由用于指定梯度线圈中的电流的梯度信号控制开环，并且放大器响应于来自梯度线圈的反馈信号而闭合运行。 DC电源可以包括多个DC单元，其可以被组合以在由线性放大器校正之前提供更精细的控制步骤。 单位可以二进制称重以提供改善的分辨率。 第二实施例中的直流电源可以包括存储电容器，其具有由放大器维持的电荷，其接收来自电容器上的峰值电荷的校正电流。

    Correction of NMR data acquired by an echo-planar technique
    5.
    发明公开
    Correction of NMR data acquired by an echo-planar technique 失效
    Korrektur der magnetischen Kernresonanz-Messwerte ermittelt durch Echoplanar-Technik。

    公开(公告)号：EP0490528A1

    公开(公告)日：1992-06-17

    申请号：EP91310952.6

    申请日：1991-11-27

    申请人： GENERAL ELECTRIC COMPANY

    发明人： Maier, Joseph Kenneth ,  Glover, Gary Harold ,  Vavrek, Robert Michael

    IPC分类号： G01R33/56

    CPC分类号： G01R33/56554

    摘要： An image data set acquired by an NMR system using an echo-planar pulse sequence is corrected for systemic errors. Errors are measured by acquiring a reference data set using the same echo-planar pulse sequence without phase encoding, and the measured errors are employed to correct phase errors in the image data set.

    摘要翻译： 通过使用回波平面脉冲序列的NMR系统获取的图像数据集被校正用于系统误差。 通过采用相位不相位编码的相同回波平面脉冲序列获取参考数据集来测量误差，采用测量误差来校正图像数据组中的相位误差。

    Gradient amplifier system for magnetic resonance imaging
    6.
    发明公开
    Gradient amplifier system for magnetic resonance imaging 失效
    系统vonGradientenverstärkernfürdie Bilderzeugung mit magnetischer Resonanz。

    公开(公告)号：EP0454298A2

    公开(公告)日：1991-10-30

    申请号：EP91302248.9

    申请日：1991-03-15

    申请人： GENERAL ELECTRIC COMPANY

    发明人： Vavrek, Robert Michael ,  McFarland, Thomas George

    IPC分类号： G01R33/38

    CPC分类号： H03F3/2178 ,  G01R33/3852 ,  H03F2200/261

    摘要： A magnetic resonance imaging system uses a pool of amplifiers (42) to generate gradient signals. Each amplifier (42a,b,c,d) within the pool may be switched among any of the gradient axes, so as to efficiently allocate amplifier power among the gradients. In one embodiment, the amplifiers (42) of the pools are connected in stacks (19) by an input and output matrix comprised of mechanical switches driven in tandem by interlocked motors. The switches connect the outputs of the amplifiers in series. The input signal is "boot strapped" through the amplifier stack to provide proper signal level.

    摘要翻译： 磁共振成像系统使用一组放大器（42）来产生梯度信号。 池内的每个放大器（42a，b，c，d）可以在任何梯度轴之间切换，以便在梯度中有效地分配放大器功率。 在一个实施例中，通过由互锁电动机串联驱动的机械开关构成的输入和输出矩阵，池的放大器（42）被堆叠（19）连接。 开关串联连接放大器的输出。 输入信号通过放大器堆栈“引导”，以提供适当的信号电平。