Table 1 Summary of EIT measures and descriptions introduced in this review
From: Clinical implication of monitoring regional ventilation using electrical impedance tomography
EIT measures | Description |
|---|---|
Tidal impedance variation (TIV) | Impedance change during a tidal breath, the difference of impedance between end-inspiration and end-expiration |
Regional respiratory system compliance | Regional compliance calculated by dividing regional TIV by driving pressure |
Overdistension and atelectasis/collapse (ODCL) | Affected area by overdistension or collapse representing reduced compliance by PEEP trial |
Center of ventilation (CoV) | Vertical shift of the ventilation distribution along the gravitational axis |
Global inhomogeneity index (GI index) | Spatial extent and dispersion in distribution of tidal breath, the overall degree of spatial heterogeneity of ventilation |
Regional ventilation delay (RVD) | Temporal delay in distribution of inspired air to reach a certain impedance change |
Intratidal gas distribution (ITV) | Changes in fraction of regional TIV with time course during inspiration |