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In this paper, an ultrasonic phased array transducer which is designed as a Cylindrical Linear Phased Array (CLPA) is presented for imaging borehole wall. Firstly, the parameters of CPLA transducer are studied, optimized, and determined based on the numerical simulation of propagation and attenuation of the radiated acoustic wave of the transducer in the borehole medium. Then a CPLA transducer is...
The uterine cervix softens, shortens, and dilates throughout pregnancy in response to progressive disorganization of its layered collagen microstructure. This process is an essential part of normal pregnancy, but premature changes are associated with preterm birth. Clinically, there are no reliable noninvasive methods to objectively measure cervical softening or assess cervical microstructure. The...
Calculating and visualizing the sound field of transducers is a key task in the development of most ultrasound applications. In most cases it is sufficient to calculate the directivity pattern or a plane slice of the sound field using the point source synthesis method. To date no freeware tool is available which is able to simulate the sound field for arbitrary rectangular transducer array matrices...
Traditional parametric arrays are produced by a second-order nonlinear interaction between two primary ultrasonic tones that are close in frequency, resulting in a difference tone that is in the audio band. This article presents a parametric array produced by a third-order nonlinear interaction between two primary ultrasonic tones that are distantly spaced in frequency such that one tone is approximately...
The goal of this study is to optimize the transfer of acoustic energy deep in the body. In order to find suitable acoustic paths for the energy transfer to be efficient, we propose a model of ultrasound propagation that takes into account a realistic geometry of the tissue layers inside the human body. The data from the Visible Human Project is used to identify the tissues between the transducer array...
Abersim, a simulation package for 3D nonlinear acoustic wave propagation of wide-band pulses from arbitrary transducers, is presented. This study validates the 3D diffraction and attenuation produced by Abersim, by comparing them to those obtained using Field II. For the presented test cases, the axial pressure amplitude and the RMS values deviate less than 0.7 dB, both for axis-symmetric and array...
This paper presents a diagnostic ultrasound imaging technique that can be used in imaging protruding objects such as a human breast using two opposing array transducers. Images are obtained in both transmission and reflection modes using two opposing linear transducer arrays. In reflection mode, images are obtained from each of both transducer arrays, and are compounded to produce a B-mode image....
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