Electrical impedance tomography using induced and injected currents

Download

029581.pdf

Date

1992-01-01

Author

Gençer, Nevzat Güneri
Kuzuoğlu, Mustafa

Metadata

Show full item record

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Item Usage Stats

214
views

268
downloads

A two-dimensional forward problem formulation is introduced for electrical impedance tomography (EIT) using induced currents. The forward problem is linearised around a certain resistivity distribution and the inverse problem is formulated as a solution of a linear system of equations. Sensitivity of boundary measurements to resistivity variations arc analysed for spatially uniform, linear and quadratic fields. The formulation, however, is suitable for studying the effects of a general magnetic field applied to induce the currents in the conductive object. A similar inverse problem formulation is also developed for EIT using injected currents. Simulation studies are performed by reconstructing images of a simulation distribution using both methods separately with generalised inversion. It is also shown that the derived formulations for the inverse problems of the two methods can be combined to solve a larger set of equations with a greater number of independent measurements.

Subject Keywords

Biophysics

URI

https://hdl.handle.net/11511/35058

Journal

CLINICAL PHYSICS AND PHYSIOLOGICAL MEASUREMENT

DOI

https://doi.org/10.1088/0143-0815/13/a/019

Collections

Department of Electrical and Electronics Engineering, Article

Suggestions

OpenMETU
Core

ANALYSIS OF 3-DIMENSIONAL SOFTWARE EIT PHANTOMS BY THE FINITE-ELEMENT METHOD Kuzuoğlu, Mustafa; IDER, YZ (IOP Publishing, 1992-01-01) In electrical impedance tomography, two-dimensional (2D) finite element solutions are used in the imaging algorithms. It is assumed that a major part of the current flowing through the object is restricted to the measurement plane (i.e. the plane determined by the electrodes which are used for measuring voltage differences) and the current flowing elsewhere is negligible. However, there is usually a three-dimensional (3D) variation of the conductivity distribution and if there are regions of high contrast c...
DETERMINATION OF THE BOUNDARY OF AN OBJECT INSERTED INTO A WATER-FILLED CYLINDER IDER, YZ; NAKIBOGLU, B; Kuzuoğlu, Mustafa; Gençer, Nevzat Güneri (IOP Publishing, 1992-01-01) In order to circumvent the electrode position determination problem in static electrical impedance tomography, it is possible to insert the object to be imaged into a water-filled cylinder on which the electrodes are at fixed and known positions. It has previously been shown that if the boundary of the internally placed object and the conductivity of the salty water in the cylinder are known, then a significant improvement in the conductivity image of the object is obtained. An algorithm for finding the bou...
Design of tunable impedance matching circuit for a GSM antenna Öztürk, Mehmet Ali; Aydın Çivi, Hatice Özlem; Koçer, Fatih; Department of Electrical and Electronics Engineering (2015) In this thesis, automatic impedance matching circuits are designed by using several tuning approaches. A typical automatic impedance matching system compensates for the impedance variations of the antenna due to the human hand and head using an electronically tunable impedance matching circuitry. Maximum output power, the linearity and efficiency of PA can be improved using automatic impedance matching circuit units. There are various tunable impedance matching circuits proposed in the literature to enhance...
Numerical analysis of ablation process on a two dimensional external surface Aykan, Fatma Serap; Dursunkaya, Zafer (2008-01-01) The thermal response analysis of an ablative material on a two dimensional external surface is performed. The method considers the whole domain as one continuous computational domain, eliminating the necessity to check the starting and ending positions of the decomposition zone. The current study solves the decomposition of the material at high temperatures by using the nth order Arrhenius equation but excludes the removal of char from the surface due to mechanical erosion or phase change and considers that...
ELECTRICAL-IMPEDANCE TOMOGRAPHY USING INDUCED CURRENTS Gençer, Nevzat Güneri; Kuzuoğlu, Mustafa (1994-06-01) The mathematical basis of a new imaging modality, Induced Current Electrical Impedance Tomography (EIT), is investigated. The ultimate aim of this technique is the reconstruction of conductivity distribution of the human body, from voltage measurements made between electrodes placed on the surface, when currents are induced inside the body by applied time varying magnetic fields. In this study the two-dimensional problem is analyzed. A specific 9-coil system for generating nine different exciting magnetic f...

Citation Formats

N. G. Gençer and M. Kuzuoğlu, “Electrical impedance tomography using induced and injected currents ,” CLINICAL PHYSICS AND PHYSIOLOGICAL MEASUREMENT, pp. 95–99, 1992, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/35058.