On the monitoring of pulmonary edema by impedance tomography

A realistic human thorax model constructed from serial CT images of a patient is used to evaluate monitoring of pulmonary edema by electrical impedance tomography (EIT). The conductivity, volume and vertical position of an abnormal region in the lungs are gradually varied to simulate the progress of edema. Dynamic EIT images are reconstructed from data computed for the inhomogeneous thorax (heart and lungs) as the reference set and a realistic amount of noise is added to reproduce the conditions in which the technique would be used in practice. Simulation results indicate that a 10 ml change in edema volume is detectable provided that the SNR of the impedance measurements is 40 dB or more.<>