Impedance spectroscopy has long been recognized as one of the major techniques for the characterization of ac transport in materials. The primary limitation of this technique is the lack of spatial resolution that precludes the equivalent circuit elements from being unambiguously associated with individual microstructural features. Here we present a scanning probe microscopy technique for quant...

An electrical impedance tomography (EIT) system images internal conductivity from surface electrical stimulation and measurement. Such systems necessarily comprise multiple design choices from cables and hardware design to calibration and image reconstruction. In order to compare EIT systems and study the consequences of changes in system performance, this paper describes a systematic approach ...

Static imaging of the electrical impedance tomography can obtain the absolute electrical conductivity distribution at one section of the subject. The test is performed on a cylinder physical phantom in which slim rectangle, hollow cylinder, small rectangle or three cylinders are selected to simulate complex conductivity perturbation objects. The measurement data is obtained by a data acquisitio...

Magnetic resonance electrical impedance tomography (MREIT) is an emerging method to visualize electrical conductivity and/or current density images at low frequencies (below 1 KHz). Injecting currents into an imaging object, one component of the induced magnetic flux density is acquired using an MRI scanner for isotropic conductivity image reconstructions. Diffusion tensor MRI (DT-MRI) measures...

The electroporation effect on tissue can be assessed by measurement of electrical properties of the tissue undergoing electroporation. The most prominent techniques for measuring electrical properties of electroporated tissues have been voltage-current measurement of applied pulses and electrical impedance tomography (EIT). However, the electrical conductivity of tissue assessed by means of vol...

Magnetic resonance electrical impedance tomography (MREIT) is a recently developed imaging technique that combines MRI and electrical impedance tomography (EIT). In MREIT, cross-sectional electrical conductivity images are reconstructed from the internal magnetic field density data produced inside an electrically conducting subject when an electrical current is injected into the subject. In thi...

The alternating current resistance and capacity of suspensions of unfertilized and fertilized eggs of Arbacia punctulata have been measured at frequencies from 10(3) to 1.64 x 10(7) cycles per second. The unfertilized egg has a static plasma membrane capacity of 0.73 microf./cm.(2) which is practically independent of frequency. The fertilized egg has a static membrane capacity of 3.1 microf./cm...

Alternating current resistance and capacity measurements have been made from 1.08 10(3) to 2.32 10(6) cycles per second on suspensions of unfertilized, fertilized, and swollen unfertilized eggs of the echinoderm Hipponoë esculenta. A simple method has been developed for measuring the volume concentration of eggs in a suspension. The membrane of the unfertilized egg is practically non-conducting...

Magnetic resonance electrical impedance tomography (MREIT) measures magnetic flux density signals through the use of a magnetic resonance imaging (MRI) in order to visualize the internal conductivity and/or current density. Understanding the reconstruction procedure for the internal current density, we directlymeasure the second derivative ofB z data from themeasured kspace data, from which we ...

In this paper, a dual frequency phase sensitive demodulation (PSD) technique is suggested to measure electrode voltages in electrical impedance tomography. The simulation results obtained by the dual frequency PSD are compared with the single frequency PSD in terms of accuracy on a simple phantom.