Numerical Simulation of Frequency-Difference EIT Using Multi-Shell Concentric Spherical Head Model

We present numerical simulations of frequency-difference electrical impedance tomography (EIT) for imaging haemorrhagic stroke inside the head adopting a multi-shell concentric spherical head model. We performed a validation study of a weighted frequency-difference method through three-dimensional numerical simulations. Adopting the multi-shell model with a frequency-dependent admittivity distribution, we investigated the performance of the method to detect a blood anomaly. We found that the simple frequency-difference method fails to detect the anomaly whereas reconstructed images using the weighted frequency-difference method clearly visualize the anomaly. We found that the weighted frequency-difference method is robust against modeling errors since it is capable of detecting an anomaly surrounded by shell-shaped obstacles simulating the internal structures of the head. We propose the weighted frequency-difference method for future studies of animal and human experiments.