Experimental Study of Noise Produced by Steady Flow Through a Simulated Vascular Stenosis

Experimental study of wall pressure fluctuations in rigid and elastic pipes behind an axisymmetric narrowing

“…Schematic of test-section with a rigid (a) and an elastic (b) measuring block: 1-silicone pipe; 2-insertion; 3-pressure sensor; 4-needle for dye injection; 5-rigid transparent glass pipe; I-flow separation region; II-flow reattachment region; III-region of flow stabilization and redevelopment into the state upstream of the insertion. Borisyuk, 1998Borisyuk, , 1999Borisyuk, , 2002Borisyuk, , 2003Iudicello et al, 1997;Mirolyubov, 1983;Wang et al, 1990;Young, 1979). The silicone elastic pipe used in the experiment satisfies these conditions.…”

“…The silicone elastic pipe used in the experiment satisfies these conditions. In addition, the choice of this pipe as a model of a larger blood vessel is because it allows close matching of other geometrical and physical parameters (see Table 1), and also because silicone pipes are widely used as a mechanical analogue of blood vessels in in vitro studies (Borisyuk, 2002;Iudicello et al, 1997;Kirkeeide et al, 1977). The use of the rigid-walled measuring block is for two reasons.…”

“…and their relation to the vortex structures behind a narrowing, as well as variation of the spectrum with axial distance from the narrowing were either not found or given insufficient attention by investigators. However, these details are important for analysis of the corresponding acoustic field (Borisyuk, 1998(Borisyuk, , 1999(Borisyuk, , 2002(Borisyuk, , 2003. Furthermore, no studies of the effect of vessel wall elasticity and narrowing length on the wall pressure characteristics are available.…”

Flow-Dependent Changes in Doppler-Derived Aortic Valve Effective Orifice Area Are Real and Not Due to Artifact

“…This technique was based on the acoustical source term computed from the velocity field and was found to be superior to other conventional methods for the determination of the diameter of vena contracta and thus of the EOA. Briefly, the flow disturbance and separation downstream from an aortic stenosis produce vortices within the flow, and in turn, these vortices generate a sound that is caused by the flow vorticity (15). This concept of sound generated by flow (i.e., hydro-acoustics) is mainly based on the vortex sound theory developed first by Lighthill (1952) (16) and then by Powell (1963) (17) and Howe (2002) (18).…”

Non-Imaging Acoustical Properties in Monitoring Arteriovenous Hemodialysis Access. A Review

“…Furthermore, they proved that different DOS percentages resulted in different energy spectra [20]. Borisyuk [38] performed in-vitro studies of the noise produced in artificial vascular stenosis. He also proved that the characteristics of stenosis are the sound intensity and increasing frequency spectra.…”