Breath samples, for analysis of breath hydrogen and methane concentrations, were collected every half hour for 4 h following consumption of the test drink.
From our 158 completed person-trips, 299 of the 316 possible samples had sufficient exhaled breath volume for analysis.
You will provide breath samples for analysis every 15 minutes.
Therefore, we suggest that exhaled breath for VOC analysis should always be collected in a standardised manner as described in the current manuscript.
There is no agreed standard for the collection of breath for volatile analysis and uncontrolled breath sampling has been shown to be unreliable (Schubert et al., 2001; O'Hara et al., 2008).
RLG was research engineer for Hamilton Medical and in charge of the logistics of the study, designed and realised the macro for breath-by-breath analysis, and was in charge of storing and securing the data.
CPET was then performed as a multistage incremental "ramp workload" study using a cycle ergometer and a metabolic cart with standardized exercise software (Medgraphic Cardio-2CP system, Medical Graphics Corporation, St. Paul, MN, USA) for breath-by-breath analysis of gas exchange.
Only the alveolar breath was used for analysis.
Off-line breath-by-breath analysis was performed on the acquired data for EAdi, Pes, flow, and Pvent waveforms for all rounds and all conditions.
EIT data were also recorded for a period of 10 minutes of spontaneous breathing in supine, prone, left- and right-lateral positions, from which a period of steady breathing (5 to 10 breaths) was used for analysis.
