E.A.Barannik Local effects of forming of an ultrasonic Doppler response of biological media |
Acoustic bulletin, Vol. 7 ¹ 2, (2004) |
| The closed solutions of parabolic diffraction equation for ultrasound wave beams irradiating by transducers with apodized apertures are used for estimation of Doppler spectra and evaluation of their bandwidth under nonfocused, focused and pulsed probing of biological media. It has been shown that under pulsed irradiation the Doppler spectrum from the flow-line is not invariant with sounding depths and depends on the positional relationship of the sample volume and the real focal point. The spectra of Doppler signals from axially-symmetrical flows with different velocity profiles were established. The developed theory is generalized on the case of spatially nonuniform movement that gives the possibility to optimize the methods of ultrasound Doppler echoscopy. |
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KEY WORDS: parabolic diffraction equation, ultrasound wave beams, the Doppler spectrum, biological media, methods of ultrasound Doppler echoscopy |
| TEXT LANGUAGE: Russian |