| Subject | Predicate | Object | Context |
|---|---|---|---|
| pubmed-article:8444681 | rdf:type | pubmed:Citation | lld:pubmed |
| pubmed-article:8444681 | lifeskim:mentions | umls-concept:C0458827 | lld:lifeskim |
| pubmed-article:8444681 | lifeskim:mentions | umls-concept:C0242485 | lld:lifeskim |
| pubmed-article:8444681 | lifeskim:mentions | umls-concept:C1704675 | lld:lifeskim |
| pubmed-article:8444681 | lifeskim:mentions | umls-concept:C0806140 | lld:lifeskim |
| pubmed-article:8444681 | lifeskim:mentions | umls-concept:C0348084 | lld:lifeskim |
| pubmed-article:8444681 | lifeskim:mentions | umls-concept:C1704474 | lld:lifeskim |
| pubmed-article:8444681 | pubmed:issue | 1 | lld:pubmed |
| pubmed-article:8444681 | pubmed:dateCreated | 1993-4-6 | lld:pubmed |
| pubmed-article:8444681 | pubmed:abstractText | Measurement of input respiratory impedance is carried out by superimposing forced oscillations on spontaneous breathing. The latter thus acts as a quasi-steady unidirectional flow component, with effects on the measured impedance that are habitually neglected (linearity assumption). We examined the validity of that assumption in the case of a turbulent steady flow. We tested the validity of a fluid dynamics criterion previously proposed in water channel experiments for gas flow in a tube. This criterion states that oscillatory and continuous turbulent flow may or may not interact if the Stokes boundary layer (ls) is embedded within the viscous sublayer (lv), i.e., if lS+ = lS/lv < or = 10, implying Re7/8 < or = (100 alpha/square root of 2), for a fully developed hydraulically smooth turbulent flow in a tube (where alpha is Womersley parameter and Re is Reynolds number of the steady-flow component). Experiments were performed in long rigid circular and semicircular tubes by superimposing two independent well-defined flows: 1) laminar oscillatory flow obeying the linear transmission line model (frequency = 1.5-250 Hz, i.e., alpha = 6-80) and 2) fully developed turbulent flow characterized by Blasius resistance formula (Re = 3,000-16,000). Confirming the validity of the criterion above, we found that the real and the imaginary parts of the long-tube impedance did not differ from those measured in the absence of a steady-flow component, provided lS+ < or = 10. On the contrary, the real parts measured with and without the continuous component differed greatly as soon as lS+ > 10, both for circular and semicircular tubes and for outward as well as inward steady flows. We concluded that the proposed criterion is pertinent for predicting appropriate oscillation frequency for a given rate of spontaneous flow, such that oscillatory and turbulent flows do not interact. Application of the forced oscillation measurement technique during spontaneous breathing requires use of a range of oscillatory frequencies higher than the frequency range classically used during apnea. | lld:pubmed |
| pubmed-article:8444681 | pubmed:language | eng | lld:pubmed |
| pubmed-article:8444681 | pubmed:journal | http://linkedlifedata.com/r... | lld:pubmed |
| pubmed-article:8444681 | pubmed:citationSubset | IM | lld:pubmed |
| pubmed-article:8444681 | pubmed:status | MEDLINE | lld:pubmed |
| pubmed-article:8444681 | pubmed:month | Jan | lld:pubmed |
| pubmed-article:8444681 | pubmed:issn | 8750-7587 | lld:pubmed |
| pubmed-article:8444681 | pubmed:author | pubmed-author:LouisBB | lld:pubmed |
| pubmed-article:8444681 | pubmed:author | pubmed-author:IsabeyDD | lld:pubmed |
| pubmed-article:8444681 | pubmed:issnType | lld:pubmed | |
| pubmed-article:8444681 | pubmed:volume | 74 | lld:pubmed |
| pubmed-article:8444681 | pubmed:owner | NLM | lld:pubmed |
| pubmed-article:8444681 | pubmed:authorsComplete | Y | lld:pubmed |
| pubmed-article:8444681 | pubmed:pagination | 116-25 | lld:pubmed |
| pubmed-article:8444681 | pubmed:dateRevised | 2008-11-21 | lld:pubmed |
| pubmed-article:8444681 | pubmed:meshHeading | pubmed-meshheading:8444681-... | lld:pubmed |
| pubmed-article:8444681 | pubmed:meshHeading | pubmed-meshheading:8444681-... | lld:pubmed |
| pubmed-article:8444681 | pubmed:meshHeading | pubmed-meshheading:8444681-... | lld:pubmed |
| pubmed-article:8444681 | pubmed:meshHeading | pubmed-meshheading:8444681-... | lld:pubmed |
| pubmed-article:8444681 | pubmed:meshHeading | pubmed-meshheading:8444681-... | lld:pubmed |
| pubmed-article:8444681 | pubmed:meshHeading | pubmed-meshheading:8444681-... | lld:pubmed |
| pubmed-article:8444681 | pubmed:meshHeading | pubmed-meshheading:8444681-... | lld:pubmed |
| pubmed-article:8444681 | pubmed:year | 1993 | lld:pubmed |
| pubmed-article:8444681 | pubmed:articleTitle | Interaction of oscillatory and steady turbulent flows in airway tubes during impedance measurement. | lld:pubmed |
| pubmed-article:8444681 | pubmed:affiliation | Institut National de la Santé et de la Recherche Médicale Unité 296, Centre Hospitalo-Universitaire Henri Mondor, Créteil, France. | lld:pubmed |
| pubmed-article:8444681 | pubmed:publicationType | Journal Article | lld:pubmed |
| pubmed-article:8444681 | pubmed:publicationType | Research Support, Non-U.S. Gov't | lld:pubmed |