Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2003-3-11
pubmed:abstractText
Transfer impedance (Ztr) of the respiratory system provides specific information on airways and tissues, but little is known about its spatial distribution in the different thoracoabdominal regions. To study Ztr distribution on the chest wall surface we analyzed five healthy subjects in the supine position by applying a sinusoidal forcing pressure (4, 8, and 12 Hz) at the mouth and measuring airway opening pressure and flow. Three-dimensional positions of 68 reflective markers placed on the chest wall over selected reference points were simultaneously measured by an optoelectronic motion analyzer. A subset of ten points placed on the midline were used to measure chest wall movements in the craniocaudal direction. While the motion of rib cage markers was synchronous, the abdominal markers demonstrated surface waves propagating caudally. The amplitude and phase of these waves were strongly dependent on position and frequency. We used a new method to measure total and local chest wall volume variations to compute the distribution of Ztr over the chest wall. Above 4 Hz we found that Ztr was inhomogeneously distributed and strongly dependent on position and frequency, mainly in the abdomen where the phase was often more more than 180 degrees with high values of modulus. For this reason, we conclude that above 8 Hz Ztr represents rib cage mechanics almost exclusively.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0090-6964
pubmed:author
pubmed:issnType
Print
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
121-31
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:12627819-Abdomen, pubmed-meshheading:12627819-Adult, pubmed-meshheading:12627819-Air Pressure, pubmed-meshheading:12627819-Airway Resistance, pubmed-meshheading:12627819-Humans, pubmed-meshheading:12627819-Image Interpretation, Computer-Assisted, pubmed-meshheading:12627819-Lung Compliance, pubmed-meshheading:12627819-Lung Volume Measurements, pubmed-meshheading:12627819-Male, pubmed-meshheading:12627819-Models, Biological, pubmed-meshheading:12627819-Motion, pubmed-meshheading:12627819-Movement, pubmed-meshheading:12627819-Oscillometry, pubmed-meshheading:12627819-Periodicity, pubmed-meshheading:12627819-Plethysmography, Whole Body, pubmed-meshheading:12627819-Pulmonary Ventilation, pubmed-meshheading:12627819-Respiratory Mechanics, pubmed-meshheading:12627819-Respiratory Physiological Phenomena, pubmed-meshheading:12627819-Rheology, pubmed-meshheading:12627819-Thorax, pubmed-meshheading:12627819-Ventilators, Mechanical, pubmed-meshheading:12627819-Video Recording
pubmed:year
2003
pubmed:articleTitle
Spatial distribution of human respiratory system transfer impedance.
pubmed:affiliation
Dipartimento di Bioingegneria, Politecnico di Milano, Italy. dellaca@biomed.polimi.it
pubmed:publicationType
Journal Article, Clinical Trial, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't