公开(公告)号：US4794338A

公开(公告)日：1988-12-27

申请号：US125659

申请日：1987-11-25

申请人： Peter B. Roemer ,  Kenneth M. Bradshaw

发明人： Peter B. Roemer ,  Kenneth M. Bradshaw

IPC分类号： G01R33/20 ,  A61B5/05 ,  G01R33/38 ,  G01R33/421 ,  H01F7/20

CPC分类号： G01R33/4215

摘要： Self-shielded gradient coils are used to eliminate interactions between gradient coils and external structure. Interactions between gradient coils for different gradient axes are controlled by means of a balanced interconnection within each separate gradient coil set. One or both of the inner and outer coils within a gradient coil set are split such that for any localized capacitive current flow between coil sets there will be an equal and opposite current flow somewhere else between the coil sets.

公开(公告)号：US5179338A

公开(公告)日：1993-01-12

申请号：US759337

申请日：1991-09-13

申请人： Evangelos T. Laskaris ,  Peter B. Roemer ,  Bizhan Dorri ,  Mark E. Vermilyea

发明人： Evangelos T. Laskaris ,  Peter B. Roemer ,  Bizhan Dorri ,  Mark E. Vermilyea

IPC分类号： G01R33/3815 ,  G01R33/385 ,  G01R33/3873 ,  G01R33/422

CPC分类号： G01R33/385 ,  G01R33/3815 ,  G01R33/3873 ,  G01R33/422

摘要： The invention relates to refrigerated superconducting MR magnets having integrated gradient coils. In particular, the amount of eddy currents produced by the magnet are substantially reduced while reducing the size and weight, and, therefore, the cost of the superconducting magnet required to produce an MR image.

摘要翻译： 本发明涉及具有积分梯度线圈的冷冻超导MR磁体。 特别地，磁体产生的涡流的量大大减小，同时减小了产生MR图像所需的超导磁体的尺寸和重量，并因此降低了超导磁体的成本。

公开(公告)号：US5017871A

公开(公告)日：1991-05-21

申请号：US407180

申请日：1989-09-14

申请人： Otward M. Mueller ,  Peter B. Roemer ,  William A. Edelstein

发明人： Otward M. Mueller ,  Peter B. Roemer ,  William A. Edelstein

IPC分类号： G01R33/20 ,  A61B5/055 ,  G01R33/385

CPC分类号： G01R33/3852

摘要： A gradient current speed-up circuit, for use in a higher-speed NMR imaging system with a gradient power amplifier and an associated gradient, coil, has a high-voltage power supply which is selectively connected to the associated gradient coil, typical via a plurality of semiconductor switching elements, to supply a pulse of a very high voltage when fast coil rise and fall times are needed. The gradient coil is connected between selected ones of semiconductors devices which are turned on and off in selected patterns, to cause the direction of coil current flow to be determined.

公开(公告)号：US4614930A

公开(公告)日：1986-09-30

申请号：US715709

申请日：1985-03-25

申请人： John S. Hickey ,  Peter B. Roemer

发明人： John S. Hickey ,  Peter B. Roemer

IPC分类号： G01R33/383 ,  A61B5/055 ,  A61B10/00 ,  G01R33/20 ,  H01F7/02

CPC分类号： H01F7/0278

摘要： A permanent magnet assembly for use in magnetic resonance imagers requires a minimum of permanent magnet material. The magnets are arranged with a radial direction of magnetization and an iron return path is used. The specific configurations of the permanent magnets provide highly uniform magnetic fields in the bore of the assembly.

摘要翻译： 用于磁共振成像器的永磁体组件需要最少的永久磁铁材料。 磁体被布置成具有径向磁化方向，并且使用铁返回路径。 永磁体的具体构造在组件的孔中提供高度均匀的磁场。

公开(公告)号：US5804969A

公开(公告)日：1998-09-08

申请号：US847431

申请日：1997-04-24

申请人： Jianyu Lian ,  Peter B. Roemer

发明人： Jianyu Lian ,  Peter B. Roemer

IPC分类号： G01R33/3415 ,  G01R33/32

CPC分类号： G01R33/3415

摘要： An MRI RF coil has two resonant rings disposed along an axis. The resonant rings are inductively coupled, but are otherwise electrically isolated from one another. In an assembly having two such MRI RF coils, a decoupling element (e.g., a decoupling capacitor or inductor) electrically connected between one ring of one coil and one ring of the other coil decouples the coils.

摘要翻译： MRI RF线圈具有沿轴线设置的两个谐振环。 谐振环感应耦合，但彼此电隔离。 在具有两个这样的MRI RF线圈的组件中，电连接在一个线圈的一个环和另一个线圈的一个环之间的去耦元件（例如，去耦电容器或电感器）使线圈解耦。

公开(公告)号：US5270657A

公开(公告)日：1993-12-14

申请号：US965131

申请日：1992-10-22

申请人： William F. Wirth ,  Thomas G. McFarland ,  Robert M. Vavrek ,  Peter B. Roemer ,  Otward M. Mueller ,  John N. Park

发明人： William F. Wirth ,  Thomas G. McFarland ,  Robert M. Vavrek ,  Peter B. Roemer ,  Otward M. Mueller ,  John N. Park

IPC分类号： G01R33/385 ,  G01V3/00

CPC分类号： G01R33/3852

摘要： A gradient amplifier for use in magnetic resonance imaging equipment employs a low voltage DC power supply connected in series between a pair of higher voltage DC power supplies, the latter supplies serving to provide increased power for rapid gradient switching and the former supply providing correction current to produce the desired voltage output. The high voltage DC power supplies preferably comprise multiple DC units which can be combined to provide finer steps of control prior to correction by the lower voltage supply. The low voltage DC power supply preferably comprise one or more linear amplifiers connected in series, or one or more switchmode amplifiers connected in series. The DC power supplies are controlled in an open loop manner from a gradient signal that designates the desired current for the gradient coil and the amplifiers are operated in a closed loop responding to to a feedback signal from the gradient coil.

摘要翻译： 用于磁共振成像设备的梯度放大器采用串联连接在一对高压直流电源之间的低压直流电源，后者用于为快速梯度切换提供增加的功率，而前一个电源提供校正电流 产生所需的电压输出。 高压DC电源优选地包括多个DC单元，其可以组合以在由较低电压源进行校正之前提供更精细的控制步骤。 低压DC电源优选地包括串联连接的一个或多个线性放大器或串联连接的一个或多个开关模式放大器。 直流电源由开路环路控制，该梯度信号指定用于梯度线圈的期望电流，并且放大器响应于来自梯度线圈的反馈信号在闭环中工作。

公开(公告)号：US5105153A

公开(公告)日：1992-04-14

申请号：US533210

申请日：1990-06-04

申请人： Otward M. Mueller ,  Peter B. Roemer

发明人： Otward M. Mueller ,  Peter B. Roemer

IPC分类号： A61B5/055 ,  G01R33/385 ,  G01R33/48 ,  H01F7/20

CPC分类号： G01R33/3852

摘要： A gradient current speed-up circuit, for use in a higher-speed NMR imaging system having an associated gradient coil, has a gradient power amplifier receiving an input analog signal controlling the current in an amplifier output circuit connected in series between first and second portions of a single gradient coil. Semiconductor switching elements selectively connect the coil portion-amplifier-coil portion between first and second potential sources, and are turned on and off in selected patterns to cause a current to be suddenly applied to, and removed from, flow through the associated gradient coil and the amplifier output circuit.

公开(公告)号：US4910462A

公开(公告)日：1990-03-20

申请号：US344642

申请日：1989-04-28

申请人： Peter B. Roemer ,  William A. Edelstein

发明人： Peter B. Roemer ,  William A. Edelstein

IPC分类号： G01R33/3815 ,  A61B5/055 ,  G01R33/38 ,  G01R33/385 ,  H01F7/20

CPC分类号： G01R33/385

摘要： An etched coil for producing a Z-axis magnetic field gradient responsive to flow of a current I, has a number N of pairs of elongated conductive strips, with each strip of a pair being positioned substantially symmetrically about a central insulative cutline, and insulatively spaced from all other strips, and with a first strip being insulatively severed into first and third strip portions; the strips are connected so that current flows into a first one of said strips and then between each successive pair of the strips until the current flows out of a last one of the strips. There are interconnectors used, in each i-th pair, where 1

公开(公告)号：US4885539A

公开(公告)日：1989-12-05

申请号：US202624

申请日：1988-06-06

申请人： Peter B. Roemer ,  Paul A. Bottomley ,  William A. Edelstein

发明人： Peter B. Roemer ,  Paul A. Bottomley ,  William A. Edelstein

IPC分类号： A61B5/055 ,  G01R33/34 ,  H01F7/20

CPC分类号： G01R33/34046

摘要： A RF volume coil with optimized signal-to-noise ratio, for NMR use, has a reduced length L.sub.c, which is between about 0.3r.sub.s and about 1.5r.sub.s, where r.sub.s is the radius of a sample-to-be-investigated, contained within the cylindrical volume coil, with the volume coil radius r.sub.c being between about 1.0r.sub.s and about 1.6r.sub.s. the "short" volume coil has an improved SNR for a voxel located substantially on the central plane of the coil, relative to the SNR of a "normal"-lenth volume coil with L.sub.c .gtoreq.4r.sub.s.

公开(公告)号：US5484985A

公开(公告)日：1996-01-16

申请号：US291260

申请日：1994-08-16

申请人： William A. Edelstein ,  Icko T. Iben ,  Otward M. Mueller ,  Egidijus E. Uzgiris ,  Peter B. Roemer

发明人： William A. Edelstein ,  Icko T. Iben ,  Otward M. Mueller ,  Egidijus E. Uzgiris ,  Peter B. Roemer

IPC分类号： B09C1/06 ,  E21B36/04 ,  E21B43/00 ,  H05B6/62 ,  H05B6/54

CPC分类号： B09C1/06 ,  E21B36/04 ,  E21B43/003 ,  H05B6/62 ,  B09C2101/00

摘要： An in-situ method of extracting contaminants from a soil volume comprises applying a radiofrequency (RF) excitation signal to heat the soil with an array of electrodes. The electrodes are inserted into the contaminated volume or inserted into a matrix of holes drilled into the volume. A first row of electrodes is electrically coupled to a shield of a coaxial cable, with a second row electrically coupled to the central conductor of the coaxial cable. RF energy is applied to pairs of electrode rows through the coaxial cable and a matching network is installed in front of the electrode-row pair to maximize power flow into the electrode-row pair. This results in very evenly distributed voltages which results in even heating. A balanced-to-unbalanced transformer (balun) is installed at the input to the matching network to prevent the deposition of RF energy outside the target volume and creation of voltages that could be hazardous to personnel. The electrodes are perforated and connected to collection tubes which collect volatilized contaminant vapors and pass the vapors to a vapor treatment unit for neutralization.

摘要翻译： 从土壤体积中提取污染物的原位方法包括施加射频（RF）激发信号以用电极阵列加热土壤。 电极被插入到污染的体积中或插入钻孔体积中的孔的矩阵中。 第一排电极电耦合到同轴电缆的屏蔽，第二行电耦合到同轴电缆的中心导体。 RF能量通过同轴电缆施加到电极对对，并且匹配网络安装在电极列对的前面，以最大限度地增加流入电极列对的功率。 这导致非常均匀的分布电压，这导致均匀的加热。 平衡不平衡变压器（平衡 - 不平衡转换器）安装在匹配网络的输入端，以防止射频能量沉积在目标体积之外，并产生可能对人员造成危害的电压。 电极被穿孔并连接到收集挥发性污染物蒸汽并将蒸气传递到蒸气处理单元进行中和的收集管中。