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EIDORS: Electrical Impedance Tomography and Diffuse Optical Tomography Reconstruction Software

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Reconstruction of real and complex components

Many EIT systems allow measurement of the in-phase and quadrature signals from the voltage data. From these data a complex measurement phasor is calculated. Image can be directly reconstructed, although there are some challenges in showing the images.

Simulation of data with real and complex components

imdl = mk_common_model('h2d1c',16);
img = mk_image(imdl,1);
vh = fwd_solve(img);

DeltaC1 = -0.1;    %Target 1 is non_conductive
DeltaC2 = 0+0.1i;  %Target 2 has + permittivity
target= mk_c2f_circ_mapping(img.fwd_model, [[0.5;0.0;0.1],[-0.5;0;0.1]]);
img.elem_data = 1+ DeltaC1*target(:,1) + DeltaC2*target(:,2) ;
vi = fwd_solve(img);
vi = add_noise(5,vi,vh);

img.calc_colours.component = 'real';
subplot(221); show_fem(img);
title 'real conductivity change'
print_convert real_complex01a.png 

img.calc_colours.component = 'imag';
subplot(221); show_fem(img);
title 'imag conductivity change'
print_convert real_complex01b.png 



Figure: Simulated conductivity (left) and permittivity (right) changes in a circular tank

Reconstruction of real and complex changes

% Create reconstruction model + solve
imdl = mk_common_model('b2d1c',16);
imgr = inv_solve(imdl, vh, vi);

imgr.calc_colours.clim = 0.02;
subplot(221); show_fem(imgr);
title 'real conductivity change'
print_convert real_complex02a.png 

imgr.calc_colours.component = 'imag';
subplot(221); show_fem(imgr);
title 'imag conductivity change'
print_convert real_complex02b.png 


Figure: Reconstructed conductivity (left) and permittivity (right) changes.

Reconstruction of real and complex changes (tank measurements)

% load data with complex measurements
load iirc_data_2006
vi= v_rotate(:,9); vh= v_reference;

imgr = inv_solve(imdl, vh, vi);

subplot(221); show_fem(imgr);
title 'real conductivity change'
print_convert real_complex03a.png 

imgr.calc_colours.component = 'imag';
subplot(221); show_fem(imgr);
title 'imag conductivity change'
print_convert real_complex03b.png 


Figure: Reconstructed conductivity (left) and permittivity (right) changes from saline tank measurements at IIRC (Korea)

Last Modified: $Date: 2017-02-28 13:12:08 -0500 (Tue, 28 Feb 2017) $ by $Author: aadler $