Characteristics of electrical impedance tomography in healthy people and its normal range

  Objective  To investigate the normal range of electrical impedance tomography (EIT) measurements in lung tissue of healthy volunteers in Beijing area.

  Methods  A total of 102 healthy volunteers (51 males and 51 females) were selected by stratified sampling method, and global impedance (GI) as well as region of interest (ROI) were collected for calm breathing and maximum breathing in sitting and supine positions, respectively. Impedance ranges for age, sex, body mass index (BMI) and other stratified factors were analyzed.

  Results  The GI and ROI of both males and females in maximal breathing state were higher than those in calm breathing state. The GI and ROI of males were higher than that of females (except in the decubitus position with calm breathing). In four ROIs, ROI2 and ROI3 accounted for higher proportions of GI in both males and females.

  Conclusion  The basic range values of EIT in healthy volunteers in Beijing area are measured in this study, which can be used as a reference for EIT system research and clinical use.