Document Detail

Wave propagation with different pressure signals: an experimental study on the latex tube.
MedLine Citation:
PMID:  8231298     Owner:  NLM     Status:  MEDLINE    
To have deeper insight into the main factors affecting wave propagation in real hydraulic lines, we measured the true propagation coefficient in two latex rubber tubes via the three-point pressure method. The measurements were performed using both sinusoidal pressure signals of different amplitudes and periodic square waves as well as aperiodic pressure impulses. The results obtained were then compared with those predicted by a classic linear model valuable for a purely elastic maximally tethered tube. Our measurements demonstrate that the three-point pressure method may introduce significant errors at low frequencies (below 1 Hz in the present experiments) when the distance between two consecutive transducers becomes much lower than the wavelength. The pattern of phase velocity in the range 2-20 Hz turns out to be about 10 per cent higher than the theoretical one computed using the static value of the Young modulus. This result supports the idea that the dynamic Young modulus of the material is slightly higher than that measured in static conditions. The experimental attenuation per wavelength is significantly higher than the theoretical one over most of the frequencies examined, and settles at a constant value as frequency increases. Introduction of wall viscoelasticity in the theoretical model can explain only a portion of the observed high frequency damping and wave attenuation. Finally, increasing the amplitude of pressure changes significantly affects the measured value of the propagation coefficient, especially at those frequencies for which direct and reflected waves sum together in a positive fashion. In these conditions we observed a moderate increase in phase velocity and a much more evident increase in attenuation per wavelength.
M Ursino; E Artioli; M Gallerani
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Medical & biological engineering & computing     Volume:  31     ISSN:  0140-0118     ISO Abbreviation:  Med Biol Eng Comput     Publication Date:  1993 Jul 
Date Detail:
Created Date:  1993-12-01     Completed Date:  1993-12-01     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  7704869     Medline TA:  Med Biol Eng Comput     Country:  ENGLAND    
Other Details:
Languages:  eng     Pagination:  363-71     Citation Subset:  IM    
Department of Electronics, Computer Science and Systems, Bologna, Italy.
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MeSH Terms
Arteries / physiology*
Models, Cardiovascular*

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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