An Electronic Mesh phantom for planar structure EIS systems

There are two phantom types to assess EIT or EIS systems: physical and electronic phantoms. The physical phantom that is used for EIT or EIS systems typically is composed of a conductive saline solution or gel medium with objects embedded in this medium. The medium and object have different impedances, which permit the system to detect changes of impedance and image them. Physical phantoms have common problems of: short life, inflexibility, instability and uncontrollable physical characteristics. The E-phantom is used to assess the system characteristics of the EIT or EIS systems such as: current or voltage delivered, internal stray impedance and the effects of the impedance of the medium on the measurements. These results can then be used to optimise the electronic circuitry and components relevant to the impedance measurements to improve the performance of the system. Thus, the advantages of an E-phantom compared with a physical phantom are: improved quality, reproducibility, predictability and stability of signals. The Sussex EIS system is based on a planar 85-electrodes structure located at the bottom of the tank. Figure 1 shows planar 85-electrodes and 2D and 3D meshes of the system