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Iowa State University

2005

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Full-Text Articles in Engineering

A Model For Estimating Ultrasound Attenuation Along The Propagation Path To The Fetus From Backscattered Waveforms, Timothy A. Bigelow, William D. O'Brien Aug 2005

A Model For Estimating Ultrasound Attenuation Along The Propagation Path To The Fetus From Backscattered Waveforms, Timothy A. Bigelow, William D. O'Brien

Timothy A. Bigelow

Accurate estimates of the ultrasound pressure and/or intensity incident on the developing fetus on a patient-specific basis could improve the diagnostic potential of medical ultrasound by allowing the clinician to increase the transmit power while still avoiding the potential for harmful bioeffects. Neglecting nonlinear effects, the pressure/intensity can be estimated if an accurate estimate of the attenuation along the propagation path (i.e., total attenuation) can be obtained. Herein, a method for determining the total attenuation from the backscattered power spectrum from the developing fetus is proposed. The boundaries between amnion and either the fetus' skull or soft tissue are each …


Estimation Of Total Attenuation And Scatterer Size From Backscattered Ultrasound Waveforms, Timothy A. Bigelow, Michael L. Oelze, William D. O'Brien Mar 2005

Estimation Of Total Attenuation And Scatterer Size From Backscattered Ultrasound Waveforms, Timothy A. Bigelow, Michael L. Oelze, William D. O'Brien

Timothy A. Bigelow

Quantitative ultrasound techniques using backscattered echoes have had limited success in vivo due to the frequency-dependent attenuation along the entire propagation path masking the frequency dependence of the backscatter. Herein, total attenuation and scatterer size are estimated simultaneously by an analysis of the in vivo backscattered power spectrum using two approaches. The simulations used to evaluate the two approaches used frequencies between 4 and 11 MHz with an effective scatterer radius of 25 μm. The first approach was based on approximations of the in vivo backscattered power spectrum (i.e., assumed Gaussian function), wherein attenuation and size were estimated by assuming …