Gas Exchange Measurements with High Temporal Resolution: The Breath-by-Breath Approach

Abstract

Respiratory gas analysis as an indicator for metabolic strain during exercise has a long history. First introduced in the 18th century, huge gas collectors served for the determination of oxidative energy delivery. While still being accepted as accurate, this particular method delivers data of low temporal resolution only. Further developments of gas analysis techniques therefore focused on a higher density of data. When algorithms became available for indispensable calculations, the so-called "breath-by-breath" (BBB) method was established some decades ago. Thereby, the term BBB in the narrower sense means that a particular physiologic value is determined for each of a subject's single respiratory cycles. Reliable application of this approach depends on the performance of available computer systems, the quality of the analyzing software routines, and the responsiveness of the gas analyzers. Thus, it appears that even nowadays technical progress is continuing in this area. This review describes technical aspects and prerequisites of the BBB approach and its specific areas of application.

Algorithms, modelling and $$ \dot{V}{\text{O}}_{ 2} $$ kinetics

“…Should the correction for transport time delay be neglected, it would heavily affect the B-by-B measurement of O 2 and CO 2 flows (an underestimation of about 30% compared to the true values has been reported during tidal ventilation; Roecker et al 2005).…”

“…Therefore, separate transport time delays should be obtained for each of the gases utilised in the B-by-B analysis, at least before each experiment. Moreover, since this parameter has been shown to consistently increase with increasing ventilation and workload intensity (Roecker et al 2005), it should be re-determined as frequently as possible.…”

“…Moreover, although rather expensive, they offer the opportunity to determine several gases simultaneously with good temporal resolution, a necessary option when one aims to describe B-by-B DVO 2s (see B-by-B alveolar-to-capillary gas transfer in this paper). Yet, whenever the time constant of a gas analyser's response exceeds 25 ms, a compensation should be made to avoid a substantial underestimation of the gas exchange rate, especially at high breathing frequencies (Roecker et al 2005). Several methods were proposed to restore the input signal from the recorded output by knowing the dynamic behaviour of the gas analyser (Arieli and Van Liew 1981;Mitchell 1979;Noguchi et al 1982).…”

Physiological characteristics of badminton match play

“…This might be due to the fact that the utilized metabolic systems were working on a mixing chamber principle analysing data every 10 or 15 s. Because mean rally times in tennis or badminton last between 5 and 10 s (Cabello Manrique and Gonzalez-Badillo 2003;Glaister 2005;Smekal et al 2001), it is questionable if mixing chamber systems can adequately reXect the intermittent nature of such sports. Roecker et al (2005) emphasized that a breathby-breath (BBB) analysis of respiratory data is most speciWc to analyse VO 2 kinetics during exercise with sudden changes in work load. This procedure enables the calculation of moving averages of sampling windows adequately reXecting the temporal structure of the speciWc sports.…”

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

“…Should this correction be neglected, it would heavily affect the BbB values, up to an underestimation of about 30 % compared to the true values (Capelli et al 2011). Of note, the delay times might also change with respect to changes in the breathing pattern (Roecker et al 2005), thus the software ideally should include variable correction factors for each breath.…”