Measuring lung resistivity using electrical impedance tomography

The use of electrical impedance tomography (EIT) imaging techniques in the measurement of lung resistivity for detection and monitoring of apnea and edema is proposed. In EIT, currents are injected into a subject using multiple electrodes, and boundary voltages are measured to reconstruct a cross-sectional image of internal resistivity distribution. It is found that a simplified, therefore fast, version of the impedance imaging method can be used for detection and monitoring of apnea and edema. The feasibility of this method has been shown through computer simulations and human experiments. The authors speculate that the EIT imaging technique will be more reliable than the current impedance apnea monitoring method, since they are monitoring the change of internal lung resistivity. However, more study is required to verify that this method performs better in the presence of motion artifact than the conventional two-electrode impedance apnea monitoring method.