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VLSI circuits for adaptive digital beamforming in ultrasound imaging
(IEEE, 1993)
For phased-array ultrasound imaging, alternative beamforming techniques and their VLSI circuits are studied to form a fully digital receive front-end hardware. In order to increase the timing accuracy in beamforming, a ...
A phase aberration correction method for ultrasound imaging
(IEEE, 1993)
A computationally efficient method for phase aberration correction in ultrasound imaging is presented. The method is based on time delay estimation via minimization of the sum of absolute differences between radio frequency ...
Characterization of layered materials by the lamb wave lens
(IEEE, 1990)
The Lamb wave lens is a type of lens that can replace the conventional lens of an acoustic microscope for some applications. When it insonifies a layered solid structure, it excites a single mode in the structure, provided ...
A new directional acoustic lens: V-groove lens
(IEEE, 1993)
A new directional acoustic lens is introduced. The geometry is very similar to the line-focus lens except the lens cavity, which is shaped as a groove with flat-bottom V cross section. The slanted planar edges of the groove ...
Fresnel lamb wave and V-groove lenses with tunable mode selectivity
(IEEE, 1995)
The Lamb wave and V-groove lenses are distinguished by their high surface wave excitation efficiencies. However, due to the fixed incidence angle, a particular lens can only be used for materials having surface wave ...
Lens geometries for quantitative acoustic microscopy
(Springer, 1995)
The purpose of the first Lemons-Quate acoustic microscope(1) was to image the surfaces of materials or biological cells with a high resolution. Unfortunately, competition with the optical microscope was only partially ...
Influence of missing array elements on phase aberration correction for medical ultrasound
(IEEE, 1994)
The influence of missing array elements on aberration correction based on time delay estimation using radio frequency signals of neighboring elements is experimentally investigated. Normalized cross correlation and sum of ...
Bi-angular lens for material characterization
(IEEE, 1994)
In this paper a new lens design is proposed for characterization of layered materials. Lamb wave lens employs Lamb waves for this purpose since these waves propagate along interfaces. However, below cut-off angle, the ...
Reduction of effects of inactive array elements in phase aberration correction
(IEEE, 1993)
Phase aberration correction based on time delay estimation via minimization of sum of absolute difference (SAD) between radio frequency (RF) signals of neighboring elements is studied in the presence of missing elements. ...
Characterization and imaging with lamb wave lens at gigahertz frequencies
(IEEE, 1994-10-11)
Lamb wave lenses with conical refracting surfaces are fabricated for use at 400 MHz and 1 GHz. The conical surfaces are ground and polished with mechanical means and they are sufficiently smooth for the frequencies of ...