Process for producing optimal current patterns for electrical impedance
tomography
    3.
    发明授权
    Process for producing optimal current patterns for electrical impedance tomography 失效
    用于产生电阻抗层析成像的最佳电流模式的过程

    公开(公告)号:US5588429A

    公开(公告)日:1996-12-31

    申请号:US317678

    申请日:1994-10-05

    CPC分类号: G01R27/26 A61B5/0536

    摘要: In electrical impedance tomography systems, the precision of voltage measurement is a critical factor in the results. Usually, the voltage values to be measured are limited by the necessity of limiting currents through the body to safe values. An effective method for increasing the apparent precision of the voltmeters is to use non-sinusoidal current patterns that produce the largest voltage variations in regions of most importance. This invention discloses several improvements in the methods by which the images resulting from any system of hardware that permits simultaneous injection of currents to all electrodes and voltage measurements at all electrodes, may be improved. One such improvement is a technique to find the shapes of the best current patterns to distinguish two different distributions of admittivity, conductivity, and permittivity in the region surrounded by electrodes. Another is a more complex procedure for finding the best shapes of the current patterns to best characterize an unknown pattern of admittivity, conductivity, or permittivity. Yet another is a procedure for calculating the values of voltages that would have been measured had sinusoidal sets of current been used, when actually using non-sinusoidal current patterns. This permits any standard reconstruction algorithm based on sinusoidal currents to be used with non-sinusoidal currents.

    摘要翻译: 在电阻抗层析成像系统中,电压测量的精度是结果的关键因素。 通常,要测量的电压值受限于通过机体将电流限制到安全值的必要性。 提高电压表的精确度的有效方法是使用非正弦电流模式,在最重要的区域产生最大的电压变化。 本发明公开了一些改进方法,通过该方法可以改善任何允许同时向所有电极注入电流的硬件系统和所有电极的电压测量所产生的图像。 一种这样的改进是找到最佳电流模式的形状的技术,以区分由电极围绕的区域中的两个不同的导纳率,导电率和介电常数的分布。 另一个是更复杂的程序,用于找到当前图案的最佳形状,以最佳地表征未知的导入性,导电性或介电常数。 另一个是当实际使用非正弦电流模式时计算已经使用正弦组电流的电压值的过程。 这允许基于正弦电流的任何标准重建算法与非正弦电流一起使用。

    Three-dimensional impedance imaging processes
    4.
    发明授权
    Three-dimensional impedance imaging processes 失效
    三维阻抗成像过程

    公开(公告)号:US5284142A

    公开(公告)日:1994-02-08

    申请号:US808795

    申请日:1991-12-16

    摘要: A method of practicing electrical impedance tomography produces three-dimensional images of a body. First, one applies certain special current patterns to the body through an array of electrodes attached to the surface. For each current pattern, one measures the voltage at each electrode, thus obtaining a corresponding pattern of voltages. These data are then used in a certain special reconstruction process, which enables a full three-dimensional reconstruction to be done in a short time. The result is a display of an approximation to the electric conductivity and/or electric permittivity in the interior of the body.

    摘要翻译: 实施电阻抗层析成像的方法产生身体的三维图像。 首先,通过附着在表面上的电极阵列,将一些特殊的电流图案应用于身体。 对于每个电流模式,一个测量每个电极处的电压,从而获得相应的电压模式。 然后将这些数据用于特定的重建过程,这使得能够在短时间内进行完整的三维重建。 结果是对身体内部的电导率和/或电介质的近似显示。

    Process and apparatus for distinguishing conductivities by electric
current computed tomography
    5.
    发明授权
    Process and apparatus for distinguishing conductivities by electric current computed tomography 失效
    通过电流计算机断层扫描来区分电导率的方法和装置

    公开(公告)号:US4920490A

    公开(公告)日:1990-04-24

    申请号:US149407

    申请日:1988-01-28

    申请人: David Isaacson

    发明人: David Isaacson

    IPC分类号: A61B5/053

    CPC分类号: A61B5/0536

    摘要: A method and apparatus for an electric current computed tomography system having an array of electrodes determines the best pattern of currents to apply to the electrodes based on the precision of the system for distinguishing between a known conductivity in a body and an unknown conductivity. An arbitrary current pattern is first applied to the array, which is at the surface of the body. Measurements are then taken for the resulting voltage pattern of the unknown conductivity. Calculations are then made to determine the calculated voltage pattern for the selected conductivity. The absolute value of the difference between the calculated and measured voltage patterns are then taken and, from this, a new current pattern is calculated. If the difference between the new current pattern and the arbitrary current pattern is less than the precision of the system, the arbitrary current pattern is applied to the electrodes. More likely, however, the difference will be greater than the precision. In this case, the new current pattern is applied to the electrodes and the measurements and calculations are repeated to generate a still further new current pattern. The difference between the previous and the new current pattern is then taken and again compared to the precision of the system. By repeating this process, the best current pattern is eventually reached.

    摘要翻译: 具有电极阵列的电流计算机断层摄影系统的方法和装置基于用于区分身体中的已知电导率和未知电导率的系统的精度来确定施加到电极的最佳电流模式。 首先将任意的电流模式应用于位于身体表面的阵列。 然后测量未知导电率的所得电压模式。 然后进行计算以确定所选导电率的计算电压模式。 然后计算和测量的电压模式之间的差值的绝对值,并从中计算新的电流模式。 如果新的电流模式和任意电流模式之间的差小于系统的精度,则将任意电流模式应用于电极。 然而,更可能的是,差异将大于精度。 在这种情况下,将新的电流模式应用于电极,并且重复测量和计算以产生更进一步的新的电流模式。 然后采用先前和新的当前模式之间的差异,并再次与系统的精度进行比较。 通过重复此过程,最终达到最佳的当前模式。

    Iterative approach for applying multiple currents to a body using voltage sources in electrical impedance tomography
    6.
    发明申请
    Iterative approach for applying multiple currents to a body using voltage sources in electrical impedance tomography 审中-公开
    在电阻抗断层扫描中使用电压源将多个电流施加到身体的迭代方法

    公开(公告)号:US20050251062A1

    公开(公告)日:2005-11-10

    申请号:US11124246

    申请日:2005-05-06

    IPC分类号: A61B5/05 A61B5/053

    CPC分类号: A61B5/0536

    摘要: Voltage sources produce desired current patterns in an ACT-type Electrical Impedance Tomography (EIT) system. An iterative adaptive algorithm generates the necessary voltage pattern that will result in the desired current pattern. The convergence of the algorithm is shown under the condition that the estimation error of the linear mapping from voltage to current is small. The simulation results are presented along with the implication of the convergence condition.

    摘要翻译: 电压源在ACT型电阻抗层析成像(EIT)系统中产生所需的电流模式。 迭代自适应算法产生将导致所需电流模式的必要电压模式。 在从电压到电流的线性映射的估计误差小的条件下示出了算法的收敛。 仿真结果与收敛条件的含义一起呈现。

    Current patterns for impedance tomography
    8.
    发明授权
    Current patterns for impedance tomography 失效
    阻抗断层扫描的当前模式

    公开(公告)号:US5272624A

    公开(公告)日:1993-12-21

    申请号:US591615

    申请日:1990-10-02

    IPC分类号: A61B5/053 G06F15/42

    CPC分类号: A61B5/0536

    摘要: In an electrical impedance imaging system that is capable of forming images based on internal resistivity of a body, an array of electrodes is applied to the surface of the body and energized by a plurality of current generators. Each current generator is controlled to produce current patterns containing single fixed magnitudes. The current generators are also controlled to apply current to the respective electrode only when the current generator is at peak current value to minimize transient conditions and maximize the rate at which images can be produced.

    摘要翻译: 在能够基于身体的内部电阻率形成图像的电阻抗成像系统中,电极阵列被施加到身体的表面并被多个电流发生器激励。 每个电流发生器被控制以产生包含单个固定幅度的电流模式。 仅当电流发生器处于峰值电流值时,电流发生器也被控制为仅向相应的电极施加电流,以最小化瞬态条件并使图像的产生速率最大化。

    Strained silicon-on-silicon by wafer bonding and layer transfer
    9.
    发明申请
    Strained silicon-on-silicon by wafer bonding and layer transfer 有权
    通过晶片接合和层转移来应变硅上硅

    公开(公告)号:US20050280026A1

    公开(公告)日:2005-12-22

    申请号:US10869814

    申请日:2004-06-16

    CPC分类号: H01L21/187

    摘要: A semiconductor-based structure includes first and second layers bonded directly to each other at an interface. Parallel to the interface, the lattice spacing of the second layer is different than the lattice spacing of the first layer. The first and second layers are each formed of essentially the same semiconductor. A method for making a semiconductor-based structure includes providing first and second layers that are formed of essentially the same semiconductor. The first and second layers have, respectively, first and second surfaces. The second layer has a different lattice spacing parallel to the second surface than the lattice spacing of the first layer parallel to the first surface. The method includes contacting the first and second surfaces, and annealing to promote direct atomic bonding between the first and second layers.

    摘要翻译: 基于半导体的结构包括在界面处彼此直接结合的第一和第二层。 平行于界面,第二层的晶格间距不同于第一层的晶格间距。 第一层和第二层各自由基本上相同的半导体形成。 制造基于半导体的结构的方法包括提供由基本相同的半导体形成的第一和第二层。 第一和第二层分别具有第一和第二表面。 第二层具有与第一层平行于第一表面的晶格间隔平行于第二表面的不同晶格间距。 该方法包括使第一和第二表面接触,退火以促进第一和第二层之间的直接原子结合。

    Current patterns for electrical impedance tomography
    10.
    发明授权
    Current patterns for electrical impedance tomography 失效
    电阻抗层析成像的当前模式

    公开(公告)号:US5381333A

    公开(公告)日:1995-01-10

    申请号:US734591

    申请日:1991-07-23

    摘要: A method in electrical impedance tomography uses an adaptive repeated series of calculations and measurements to determine the best current pattern for a body having an initially unknown internal conductivity, for producing the best electrical impedance image for the body. Initially, an arbitrary current pattern and conductivity is utilized to generate a voltage pattern which is measured and compared with the theoretical voltage pattern based on the arbitrary conductivity and current patterns. When both the current pattern and the conductivity yielded by the process closely match values derived by measurements, the voltage pattern is used to produce the image.

    摘要翻译: 电阻抗层析成像中的一种方法使用自适应重复的一系列计算和测量来确定具有最初未知内部电导率的身体的最佳电流模式,以产生用于身体的最佳电阻抗图像。 最初,利用任意的电流模式和电导率来产生电压模式,该电压模式根据任意的电导率和电流模式与理论电压模式进行测量和比较。 当由该过程产生的电流模式和电导率两者都非常匹配通过测量导出的值时,使用电压模式来产生图像。