Indices of acceleration atelectasis and the effect of hypergravity duration on its development.

New Findings: What is the central question of the study? The aim was to determine the effects of duration of acceleration in the cranial-caudal direction (+Gz) on acceleration atelectasis and identify measurement techniques that can be used to assess it. What is the main finding and its importance? Non-invasive measurement of acceleration atelectasis using electrical impedance tomography and estimates of pulmonary shunt provide more detailed assessment of acceleration atelectasis than traditional forced vital capacity measures. Using these techniques, it was found that as little as 30 s of exposure to +Gz acceleration can cause acceleration atelectasis.

Hemodynamic Responses and G Protection Afforded by Three Different Anti-G Systems.

UK Royal Air Force fast jet aircrew use three different anti-G systems, however, little objective comparison of the G protection they provide exists. The G-protection afforded by each system and associated hemodynamic responses were investigated. Ten subjects performed centrifuge acceleration exposures using Mk-10 (S1) and Mk-4 (S2) five-bladder anti-G trousers (AGT) and full coverage AGT plus pressure breathing for G-protection (PBG; S3).