Lung tissue measured in EIT may change depending on the positioning of electrode plane

EIT measurements were performed in 3 different transverse thoracic planes during pulmonary function test. Ratios between relative impedance changes and volume changes were different depending on the positioning of electrode planes. Since atelectasis should be minima in the healthy volunteers, the change of ratios may be explained by activity of respiratory muscles, which lead to changes in amount of lung tissue captured by EIT.