3D Geometry Design of the Human Thorax and Forward Calculation for Electrical Impedance Tomography

Electrical Impedance Tomography (EIT) for lung monitoring reflects the internal conductivity distribution of human tissues based on the boundary voltages that are measured through given electrodes. The electrodes are placed around the human chest. A low-amplitude current is injected through driving electrodes, and the boundary voltages are measured through other electrodes. In this context, this work has elaborated a strategy for the design of a 3D geometry of the human thorax based on sequential Computed Tomography (CT) scans. This geometry will be used for the simulation and analysis of the EIT measurement. Image segmentation has been used to extract the contour within different layers of the CT scans to form the final 3D geometry of the chest containing the lungs and the thorax. The generated geometry was later meshed and repaired. Mesh properties were controlled through the Skewness quality metric. A multi-layered design has been elaborated to mimic different human chest layers such as body fluid, muscle, and skin resulting in three models. These models had given the accuracy of 62%, 63%, and 65% of skewed elements relative to the existing volume. Later on, the electrodes were placed on the thorax geometry for EIT forward simulation, and the effect of the multi-layered model has been investigated.