Authors:
Víctor Hugo Mosquera
1
;
Adrian Arregui
2
;
Ramon Bragós
2
and
Carlos Felipe Rengifo
1
Affiliations:
1
University of Cauca, Colombia
;
2
Technical University of Catalonia, Spain
Keyword(s):
Electrical Impedance Tomography, Image Reconstruction, Conductivity Distribution.
Abstract:
Electrical impedance tomography (EIT) is a technique of image reconstruction of the electrical conductivity
distribution in a tissue or region under observation. An electrical system for EIT comprises complex hardware
and software modules, which are designed for a specific application which requires that the system to be able
to detect conductivity variations within the study object. The Front-End for body composition measurement,
AFE4300 from Texas Instruments allows a minimal implementation of an electrical impedance tomography
system. It is the main device in the development of the EIT system presented in this paper, this device injects
the current signal and measures the tensions generated on the study region boundary by 8 electrodes, the
image reconstruction software was developed on the National Instruments platform Labview. The system
includes a microcontroller PIC16F886 to configure the 8 channels for the definition of the patterns of injection
and measurement of sig
nals, also defines the current signal frequency and the bluetooth communication with
the computer for the image reconstruction. The developed system was validated by a planar resistive phantom
(CardiffEIT phantom), obtaining a stable voltage measurement every 50 ms per pair of electrodes, and a signal
to noise ratio (SNR) maximum of 71.8 dB, for a current signal of 50 kHz. Additionally, tests were carried out
in a saline tank with a concentration of 4 g/L, the developed system can simultaneously estimate the presence
of conductive and non-conductive disturbances into the tank.
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