Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Selective transmission of a focused Doppler ultrasound beam through a plastic layer
Autore:
Thompson, RS; Tortoli, P; Aldis, GK;
Indirizzi:
Univ Sydney, Sch Math & Stat, Sydney, NSW 2006, Australia Univ Sydney Sydney NSW Australia 2006 & Stat, Sydney, NSW 2006, Australia Univ Florence, Dept Elect Engn, Florence, Italy Univ Florence Florence Italy Florence, Dept Elect Engn, Florence, Italy Australian Def Force Acad, Sch Math, Canberra, ACT, Australia Australian Def Force Acad Canberra ACT Australia anberra, ACT, Australia
Titolo Testata:
ULTRASOUND IN MEDICINE AND BIOLOGY
fascicolo: 8, volume: 26, anno: 2000,
pagine: 1333 - 1346
SICI:
0301-5629(200010)26:8<1333:STOAFD>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
STEADY FLOW; TEST-OBJECT; REFRACTION; ARTIFACTS; INTENSITY; PHANTOM;
Keywords:
Doppler ultrasound; flow velocity measurement; refraction; elastic media; flow phantom;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Clinical Medicine
Citazioni:
23
Recensione:
Indirizzi per estratti:
Indirizzo: Thompson, RS Univ Sydney, Sch Math & Stat, Sydney, NSW 2006, Australia Univ Sydney Sydney NSW Australia 2006 y, NSW 2006, Australia
Citazione:
R.S. Thompson et al., "Selective transmission of a focused Doppler ultrasound beam through a plastic layer", ULTRASOUN M, 26(8), 2000, pp. 1333-1346

Abstract

Laboratory test objects are widely used in Doppler ultrasound (US). Although the acoustic properties of in vitro materials are usually known, they are unlikely to match each other, or their in vivo counterparts, exactly. We conducted theoretical and experimental studies of a focused ultrasound beamas it passes from one fluid, through an intervening plastic layer at an oblique angle, and then into a different fluid. Dual mode propagation may occur (i.e., both longitudinal and shear waves can propagate in the plastic layer). Our calculations show that the power transmitted by either mode dropsvery rapidly to zero at certain critical angles. A range of angles of incidence exists within a focused beam and this, combined with the highly angle-dependent power transmission behaviour, can produce major distortions of Doppler data. These may persist even when the beam axis is not oriented exactly at the critical angle. The total power transmitted depends on all the wave speeds, may involve mode conversion, and is a very complicated functionof the angle of incidence. This study reports a practical method for the calculation of power transmission though a plastic layer, and shows how the resulting power vs. angle graph can be used to avoid artefacts in in vitro Doppler studies. (C) 2000 World Federation for Ultrasound in Medicine & Biology.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 21/09/20 alle ore 02:44:31