Assessment of breath-by-breath alveolar gas exchange: an alternative view of the respiratory cycle

摘要

Breath-by-breath (BbB) determination of the O-2 flux at alveolar level implies the identification of the start and end points of each respiratory cycle; Gronlund defined them as the times in two successive breaths showing equal expiratory gas fractions. Alternatively, the start and end points of each breath might be linked to the ratio between the exchangeable and non-exchangeable gases. The alternative algorithm is described and evaluated with respect to the algorithm proposed by Gronlund.