Influence of Measurement Pattern on RAW-data in Electrical Impedance Tomography

The conductivity distribution inside a volume conductor can be reconstructed with Electrical Impedance Tomography (EIT). Therefore, electrodes on the surface of the volume conductor are used to inject a constant current and measure the resulting surface potentials, which is equivalent to transfer impedances. A sequence of current injections and voltage measurements is called measurement pattern and results in a set of transfer impedances. Various measurement patterns exist and each of them has a specific sensitivity, which influences the distinguishability of an object in the reconstructed image. To compare different patterns we introduced three criteria based on the RAW-measurement and evaluated the performance in a water-tank experiment. Measurement patterns with an increased distance between the injecting and measuring electrodes showed more sensitivity and selectivity in the RAW-data and should be preferably chosen compared to the traditional adjacent pattern.