利索-全球专利检索

  1. 登录
  2. 注册

搜索结果

32 条记录 (耗时 0.021 秒)

    Split gradient amplifier for an MRI system
    3.
    发明授权
    Split gradient amplifier for an MRI system 失效
    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。

    Gradient speed-up circuit for NMR system
    4.
    发明授权
    Gradient speed-up circuit for NMR system 失效
    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.

    Radiofrequency ground heating system for soil remediation
    5.
    发明授权
    Radiofrequency ground heating system for soil remediation 失效
    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。

    Method of, and apparatus for, NMR spectroscopic metabolite imaging and quantification
    6.
    发明授权
    Method of, and apparatus for, NMR spectroscopic metabolite imaging and quantification 失效
    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.

    Transformer-coupled gradient speed-up circuit
    7.
    发明授权
    Transformer-coupled gradient speed-up circuit 失效
    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.

    Preamplifier circuit for magnetic resonance system
    8.
    发明授权
    Preamplifier circuit for magnetic resonance system 失效
    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。

    Cryogenic capacitors
    10.
    发明授权
    Cryogenic capacitors 有权
    低温电容器

    公开(公告)号：US07126810B1

    公开(公告)日：2006-10-24

    申请号：US10875458

    申请日：2004-06-24

    申请人： Otward M. Mueller ,  Eduard K. Mueller ,  Michael J. Hennessy

    发明人： Otward M. Mueller ,  Eduard K. Mueller ,  Michael J. Hennessy

    IPC分类号： H01G4/38

    CPC分类号： H01G9/14 ,  H02J15/00 ,  Y02E40/67

    摘要： This invention describes a means by which performance characteristics of capacitors can be improved. This is achieved by reducing the temperature, preferably but not exclusively to cryogenic temperatures below 100 K. This is based on the observation that the dielectric strength, dielectric losses and plate losses in many capacitors, such as film capacitors, improve as the temperature is decreased. A cryogenic capacitor bank is also described, which exhibits energy densities up to four times those of conventional, room-temperature capacitor banks. Cryogenic capacitors can be combined with cryogenically operated semiconductors or with superconductors in such a way as to reduce the size, weight, and losses of a complete system.

    摘要翻译： 本发明描述了可以提高电容器的性能特性的方法。 这通过将温度降低，优选但不限于低于100K的低温来实现。这是基于以下观察结果：许多电容器（例如薄膜电容器）中的介电强度，介电损耗和板损耗随温度降低而改善 。 还描述了一种低温电容器组，其表现出高达常规室温电容器组的四倍的能量密度。 低温电容器可以与低温操作的半导体或超导体组合，以减小整个系统的尺寸，重量和损耗。