Preliminary results of a miniaturized respiratory sensor system used under hypergravity conditions up to 9 gz

Abstract

Respiratory gas analyses are used to explore the influence of increased gravity on the physiology of breathing. Due to the mass, size and intricacy of standard measurement systems, previous studies were limited to a maximum acceleration of + 5 gz (head-to-foot direction). Furthermore, no in situ mainstream measurements of oxygen and carbon dioxide concentration were possible under hypergravity conditions so far. This paper shows a first study which demonstrates a respiratory sensor system developed at the Institute for Aerospace Engineering at TU Dresden. This system is suitable for an in situ measurement of respiratory changes up to + 9 gz (maximum acceleration of jet pilots) and therefore provides a possibility for detailed physiological analyses in future. Three jet pilots were equipped with this system and accelerated under a defined profile up to 7, 8 and + 9 gz. The breathing air flow, oxygen and carbon dioxide concentration were recorded with our miniaturized solid state electrolyte gas sensors, which are also described in this paper. The analysed data show significant changes of the measured respiratory parameters depending on the G-level, the acceleration rate (G-rate of onset [g s−1]) and the examination time.