Avtor/Urednik		Černelč, Mateja; Suki, Bela; Reinmann, Benjamin; Hall, Graham L; Frey, Urs
Naslov		Correlation properties of tidal volume and end-tidal O2 and CO2 concentrations in healthy infants
Tip		članek
Vir		J Appl Physiol
Vol. in št.		Letnik 92, št. 5
Leto izdaje		2002
Obseg		str. 1817-27
Jezik		eng
Abstrakt		We investigated whether breath-to-breath fluctuations in tidal volume (VT) and end-tidal O(2) and CO(2) exhibit long-range correlations and whether parameters describing the correlations can be used as noninvasive descriptors of control of breathing. We measured VT and end-tidal O(2) and CO(2) over n = 352 +/- 104 breaths in 26 term, healthy, unsedated infants (mean age +/- SD: 36 +/- 6 days) and calculated the detrended fluctuation function ŠF(n)Ć. The F(n) of the breath-to-breath time series of VT, O(2), and CO(2) revealed a linear increase with a breath number on log-log plots with a slope that was significantly different from 0.5 (random) and thus consistent with scale-invariant behavior. Long-range correlations were stronger for O(2) than for VT and CO(2.) The F(n) of many individual signals exhibited a crossover behavior indicating that control mechanisms regulating fluctuations of VT, O(2), and CO(2) may be different on different time scales. Thus breathing has a memory up to at least 400 breaths that can be characterized by the simple indicator alpha.
Deskriptorji		TIDAL VOLUME PULMONARY GAS EXCHANGE CARBON DIOXIDE OXYGEN SUPINE POSITION RESPIRATORY MECHANICS INFANT