3D EIT Enables Global and Regional Spirometric Lung Function Assessment

Electrical impedance tomography (EIT) is a non-invasive and cost-effective imaging technique that reconstructs the inner conductivity distribution of a body to probe internal structures and functions. EIT has been used to construct 2D images of the lungs as a monitoring and diagnostic method. 3D EIT has a larger field of view (FOV) compared to 2D EIT, which is crucial for the accurate and comprehensive assessment of lung functions. Spirometry is the clinical standard to assess the ventilation function of the lungs, but it is only able to provide a global assessment by measuring the volume change over inhalation and exhalation. On the other hand, 3D EIT can provide both global and regional analysis. This study aims to explore 3D EIT using simulations and phantoms, validate image reconstruction algorithm in three dimensions, and test the feasibility of in vivo 3D EIT in spirometry paradigm compare with 2D EIT. A successful 3D lung EIT reconstruction was demonstrated together with global and regional analysis. The study showed high correlation between the conductivity of the lungs and the volume of the lungs. Thus, a single EIT device may complement with more functionality of the spirometer.