Two-Dimensional Forward Modeling for Human Thorax Imaging Based on Electrical Impedance Tomography

Electrical impedance tomography (EIT) is a non-invasive imaging technique for investigating the conductivity distribution within biological tissues by applying a low alternating electrical signal to the medium under test (MUT) and measuring the voltage drops resulting in defined positions. These measurements are subjected to image reconstruction algorithms to deliver the conductivity distribution in the specified MUT. As part of the EIT image reconstruction process, the forward problem is crucial, in which the MUT needs to be modeled accurately in its geometry and expected conductivity. In this paper, a 2D numerical model of the human thorax with real electrical characteristics has been elaborated using COMSOL Multiphysics. Besides, the complete electrode model (CEM) detailing the electrode-MUT interface and the effect of the contact impedance on the resulting potential distribution is studied for the two states of breathing, which are the exhale and the inhale. Finally, a generic 2D model of the human thorax is presented.