HOW TO PREPARE INPUT FILE FOR THE ON-LINE EIT RECONSTRUCTION SERVER

Suppose measuring system has 16 electrodes. In this case the data set included in text file must consist of 16*16=256 values, independently on the measurement strategy.

Consider example with POLAR current injection:

If the measuring system doesn't perform redundant measurements, as the current injection through electrodes n and m is equivalent to the injection through electrodes m and n, corresponding redundant values should be set to zeros as in the following example:

POLAR
16
0.000 0.908 0.513 0.313 0.202 0.280 0.752 0.000 0.000 0.869 0.351 0.243 0.297 0.311 0.340 0.000
0.000 0.000 1.358 0.484 0.205 0.212 0.355 1.214 0.000 0.000 0.991 0.409 0.369 0.297 0.240 1.358
1.268 0.000 0.000 1.072 0.297 0.240 0.315 0.656 1.158 0.000 0.000 0.880 0.513 0.345 0.228 0.746
0.441 0.937 0.000 0.000 0.863 0.405 0.387 0.566 0.601 0.774 0.000 0.000 1.120 0.445 0.230 0.530
0.243 0.351 1.052 0.000 0.000 0.985 0.566 0.584 0.452 0.439 0.822 0.000 0.000 1.052 0.346 0.530
0.243 0.261 0.530 1.021 0.000 0.000 1.102 0.709 0.372 0.289 0.313 0.910 0.000 0.000 0.938 0.836
0.297 0.243 0.387 0.474 0.869 0.000 0.000 1.257 0.401 0.239 0.208 0.369 1.052 0.000 0.000 1.861
0.413 0.242 0.297 0.295 0.351 0.823 0.000 0.000 0.801 0.304 0.213 0.261 0.548 1.209 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Here last 8 rows are filled with zeros, as they are equivalent to the firs 8 data rows. Note, that carrying out redundant measurements makes sense because it reduces measuring errors due to averaging at reconstruction.

For DIPOLE (adjacent) current injection:

If the measuring system doesn't perform redundant measurements, as the measuring with injecting pair n and voltage measuring pair m is equivalent to the measuring with injecting pair m and measuring pair n due to reciprocity, corresponding redundant values should be set to zeros as in the following example:

DIPOLE
16
0.000 0.000 1.072 0.271 0.121 0.064 0.050 0.067 0.071 0.064 0.055 0.073 0.150 0.303 1.219 0.000
0.000 0.000 0.000 0.954 0.227 0.090 0.058 0.061 0.049 0.030 0.022 0.024 0.042 0.065 0.138 0.703
0.000 0.000 0.000 0.000 1.086 0.229 0.110 0.102 0.061 0.033 0.020 0.019 0.026 0.035 0.052 0.131
0.000 0.000 0.000 0.000 0.000 0.908 0.228 0.176 0.093 0.040 0.022 0.018 0.023 0.028 0.035 0.066
0.000 0.000 0.000 0.000 0.000 0.000 0.827 0.306 0.135 0.047 0.023 0.017 0.018 0.020 0.023 0.038
0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.215 0.297 0.080 0.033 0.021 0.019 0.017 0.018 0.026
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.905 0.155 0.053 0.029 0.023 0.020 0.018 0.022
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.800 0.178 0.081 0.054 0.041 0.034 0.035
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.034 0.290 0.150 0.091 0.061 0.056
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.920 0.280 0.139 0.084 0.061
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.917 0.226 0.101 0.061
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.047 0.234 0.095
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.284 0.273
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 1.109
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000
0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000 0.000

Here the values, which can be found from reciprocity, are substituted by zeros. Again take into account, that carrying out redundant measurements makes sense because it reduces measuring errors due to averaging at reconstruction.

As the conclusion:
For measuring system with N electrodes and any measurement strategy the input text file for image reconstruction must consist of first line with injection strategy keyword, second line with number of electrodes N and then N*N voltages, some of which can be zeros according to particular measurement strategy.

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