O.A.Borisyuk Modeling of noise generation by a vascular stenosis |
Acoustic bulletin, Vol. 3 ¹ 2, (2000) |
| An in vitro experiment is carried out in order to study the properties of an acoustic field in human chest produced by flow in a larger blood vessel. The cases of intact and partially occluded vessels are considered, and abrupt rigid-wall hollow axisymmetric cylindrical plugs of different inner diameters and lengths are used as stenoses. The analysis of the noise fields reveals the characteristic signs of the presence of a stenotic obstruction in the vessel. These are the general increase of the noise levels and production of the new frequency components in the power spectrum. The components are identified with the characteristic frequencies of vortex formation in a disturbed flow region past stenosis and the resonance frequencies of vibrations of a poststenotic segment of vessel. The stenosis generated acoustic power is found to be approximately proportional to the fourth power of the constriction severity and fourth power of the flow Reynolds number. |
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KEY WORDS: blood vessel, stenosis, pressure fluctuations, vortex structures |
| TEXT LANGUAGE: Russian |