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1. 发明授权

US5270657A Split gradient amplifier for an MRI system 失效
标题翻译：用于MRI系统的分离梯度放大器
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。

2. 发明授权

US5063349A Transformer-coupled gradient speed-up circuit 失效
标题翻译：变压器耦合梯度速度电路
公开(公告)号：US5063349A
公开(公告)日：1991-11-05
申请号：US533233
申请日：1990-06-04
申请人： Peter B. Roemer , Otward M. Mueller , John N. Park , William McMurray
发明人： Peter B. Roemer , Otward M. Mueller , John N. Park , William McMurray
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 amplifier output current, and a transformer having a primary winding and a pair of secondary windings connected in series with the amplifier output and the coil. Semiconductor switching elements selectively connect the primary winding 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; the amplifier output current is changed with the gradient coil current lags behind an amplitude commanded by a master input signal.

3. 发明授权

US4961054A Gradient current speed-up circuit for high-speed NMR imaging system 失效
标题翻译：用于高速NMR成像系统的梯度电流加速电路
公开(公告)号：US4961054A
公开(公告)日：1990-10-02
申请号：US376074
申请日：1989-07-06
申请人： John N. Park , Otward M. Mueller , Peter B. Roemer
发明人： John N. Park , Otward M. Mueller , Peter B. Roemer
IPC分类号： G01R33/20 , A61B5/055 , G01R33/38 , G01R33/385 , G01R33/48 , H03K17/567
CPC分类号： G01R33/3852 , H03K17/567
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 an energy-storage element, with an inductance typically between 5 and 20 times the inductance of the associated gradient coil. A plurality of semiconductor switching elements receive the current output of the energy-storage element; and the associated gradient coil is connected between selected ones of these semiconductors devices. The semiconductor devices are turned on and off in selected patterns, to cause the energy-storage element current to be suddenly applied to and removed from flow through the associated gradient coil.

4. 发明授权

US5017871A Gradient current speed-up circuit for high-speed NMR imaging system 失效
标题翻译：用于高速NMR成像系统的梯度电流加速电路
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.

5. 发明授权

US5105153A Gradient speed-up circuit for NMR system 失效
标题翻译： NMR系统的梯度速度回路
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.

6. 发明授权

US5484985A Radiofrequency ground heating system for soil remediation 失效
标题翻译：射频地面加热系统土壤修复
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。

7. 发明授权

US4881032A Method of, and apparatus for, NMR spectroscopic metabolite imaging and quantification 失效
标题翻译： NMR光谱代谢物成像和定量的方法和装置
公开(公告)号：US4881032A
公开(公告)日：1989-11-14
申请号：US260633
申请日：1988-10-21
申请人： Paul A. Bottomley , Peter B. Roemer , William A. Edelstein , Otward M. Mueller
发明人： Paul A. Bottomley , Peter B. Roemer , William A. Edelstein , Otward M. Mueller
IPC分类号： A61B5/055 , G01R33/36 , G01R33/48 , G01R33/485
CPC分类号： G01R33/485 , G01R33/3628
摘要： A method for NMR spectroscopy metabolite imaging utilizes the steps of: applying to a desired portion of a sample a pulsed phase-encoding linear magnetic gradient signal in at least one of the three orthogonal dimensions of a Cartesian coordinate set, prior to acquisition of free-induction-decay NMR response signals from the sample portion; substantially eliminating from at least the sample portion eddy current fields induced responsive to the phase-encoding gradient pulses; maximizing the signal-to-noise ratio of the NMR response signals; and displaying the data resulting from Fourier transformation of the received response data. A high-field NMR imaging system is provided with self-shielded gradient coils, to subsantially remove eddy-current effects, and at least one of maximized-SNR antenna, of quadrature-driven volume RF coil and/or surface RF coil types are utilized for both transmission of the excitation RF pulses and reception of the RF response signals. The acquired FID data is filtered and a Fourier transform reconstruction, of dimension d' equal to one greater than the numder d of spatial dimensions to be displayed, is performed.

8. 发明授权

US5545999A Preamplifier circuit for magnetic resonance system 失效
标题翻译：用于磁共振系统的前置放大器电路
公开(公告)号：US5545999A
公开(公告)日：1996-08-13
申请号：US407825
申请日：1995-03-21
申请人： Otward M. Mueller , Christopher P. Yakymyshyn , Peter B. Roemer , Ronald D. Watkins
发明人： Otward M. Mueller , Christopher P. Yakymyshyn , Peter B. Roemer , Ronald D. Watkins
IPC分类号： A61M25/095 , G01R33/36 , G01V3/00
CPC分类号： G01R33/3692 , G01R33/3621
摘要： A circuit for amplifying signals received by the receive coil of a magnetic resonance (MR) system includes a preamplifier employing an active circuit device, such as a GaAs-MESFET or HEMT. The preamplifier is located proximate to the receive coil in order to maintain as high a signal-to-noise ratio as possible for the preamplifier output signals. A capacitance is coupled to the receive coil to form an input impedance matching network for the input of the preamplifier. The preamplifier output is coupled through a fiber optic cable to remotely located MR signal processing electronics, which further processes signals received by the MR receive coil and amplified by the preamplifier.
摘要翻译：用于放大由磁共振（MR）系统的接收线圈接收的信号的电路包括采用诸如GaAs-MESFET或HEMT的有源电路器件的前置放大器。前置放大器位于接收线圈附近，以便为前置放大器输出信号保持尽可能高的信噪比。电容耦合到接收线圈以形成用于前置放大器的输入的输入阻抗匹配网络。前置放大器输出通过光纤电缆耦合到远程定位的MR信号处理电子设备，其进一步处理由MR接收线圈接收并由前置放大器放大的信号。

9. 发明授权

US5027071A Method of, and apparatus for, NMR slice selection 失效
标题翻译： NMR切片选择的方法和装置
公开(公告)号：US5027071A
公开(公告)日：1991-06-25
申请号：US489124
申请日：1990-03-05
申请人： Christopher J. Hardy , Peter B. Roemer , Otward M. Mueller
发明人： Christopher J. Hardy , Peter B. Roemer , Otward M. Mueller
IPC分类号： A61B5/055 , G01R33/32 , G01R33/36 , G01R33/385 , G01R33/387 , G01R33/54 , G01R33/565 , G06T1/00
CPC分类号： G01R33/385 , G01R33/56518 , G01R33/3607 , G01R33/3852
摘要： A method of reducing slice profile degradation due to gradient signal amplitude ripple, has steps of: sensing the gradient signal ripple amplitude; normalizing the sensed ripple signal amplitude responsive to the gradient amplitude commanded; and modulating the RF signal amplitude with the adjusted-amplitude ripple signal, to cause the RF and gradient magnetic fields to have an effective vector pointing substantially in the same direction, during the slice-selection interval, as would the effective field vector formed with a gradient field devoid of ripple. Apparatus for reducing the slice profile degradation modulates the RF signal with the ripple envelope obtained from the output of the gradient signal amplifier, by a signal controlled by the gradient amplifier input.

10. 发明授权

US07369377B1 Snubbers for low temperature power electronics 有权
标题翻译：低温功率电子缓冲器
公开(公告)号：US07369377B1
公开(公告)日：2008-05-06
申请号：US11224184
申请日：2005-09-12
申请人： Michael J. Hennessy , John N. Park , Otward M. Mueller , Eduard K. Mueller
发明人： Michael J. Hennessy , John N. Park , Otward M. Mueller , Eduard K. Mueller
IPC分类号： H02H7/00 , H02H9/00 , H01L29/00 , H01L23/34
CPC分类号： H03K17/92 , H01L2924/0002 , H01L2924/00
摘要： Switching losses and conduction losses are isolated by networks which are partially cryogenic and partially at room temperature. Switching losses are independent of temperature. Advantageously the switching losses are taken in a snubber network at room temperature and conduction losses are incurred at cryogenic temperatures, where majority carrier devices like MOSFETs operate with ultra low on-state resistance and corresponding low conduction losses. Low loss leads carry current efficiently from the cryogenic environment to room temperature without adversely affecting refrigeration. Switch and snubber network may both operate cryogenically.
摘要翻译：开关损耗和传导损耗由部分低温部分在室温的网络隔离。开关损耗与温度无关。有利地，开关损耗在室温下在缓冲网络中进行，并且在低温下产生传导损耗，其中诸如MOSFET的多数载流子器件以超低导通状态电阻和相应的低导通损耗工作。低损耗引线可将电流从低温环境有效地运送到室温，而不会对制冷产生不利影响。开关和缓冲网络都可以低温运行。

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