Ultrasonic Synthetic Apertures: Review

Nowicki, Andrzej; Gambin, Barbara

doi:10.2478/aoa-2014-0047

Cited by 9 publications

(2 citation statements)

References 22 publications

(9 reference statements)

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“…2b , where a digital projector and optical microscope were used to illuminate the hydrogel with a variety of structures 36 . Furthermore, the method affords a convenient technique for producing customized microphone arrays (acoustic emitters) with tailored reception (emission) patterns suitable, for example, for synthetic aperture array SONAR or ultrasound 37 38 or for producing structured acoustic beams.…”

Section: Resultsmentioning

confidence: 99%

Hydrogel microphones for stealthy underwater listening

et al. 2016

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Exploring the abundant resources in the ocean requires underwater acoustic detectors with a high-sensitivity reception of low-frequency sound from greater distances and zero reflections. Here we address both challenges by integrating an easily deformable network of metal nanoparticles in a hydrogel matrix for use as a cavity-free microphone. Since metal nanoparticles can be densely implanted as inclusions, and can even be arranged in coherent arrays, this microphone can detect static loads and air breezes from different angles, as well as underwater acoustic signals from 20 Hz to 3 kHz at amplitudes as low as 4 Pa. Unlike dielectric capacitors or cavity-based microphones that respond to stimuli by deforming the device in thickness directions, this hydrogel device responds with a transient modulation of electric double layers, resulting in an extraordinary sensitivity (217 nF kPa−1 or 24 μC N−1 at a bias of 1.0 V) without using any signal amplification tools.

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Section: Resultsmentioning

confidence: 99%

Hydrogel microphones for stealthy underwater listening

et al. 2016

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“…In this paper, we addressed the multi-element synthetic aperture focusing technology (M-SAF) applied in ultrasound imaging using ring arrays. In [ 20 , 21 ], the concept of a synthetic aperture used for the high resolution ultrasonic imaging was introduced and focused on the research of synthetic apertures, respectively. Through the analysis of the sound field distribution of different array elements and through simulations and experiments, the best imaging results are obtained.…”

Section: Introductionmentioning

confidence: 99%

Research on the Multi-Element Synthetic Aperture Focusing Technique in Breast Ultrasound Imaging, Based on the Ring Array

Zhang

Shao

et al. 2022

Micromachines

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As a widely clinical detection method, ultrasonography (US) has been applied to the diagnosis of breast cancer. In this paper, the multi-element synthetic aperture focusing (M-SAF) is applied to the ring array of breast ultrasonography (US) imaging, which addresses the problem of low imaging quality due to the single active element for each emission and the reception in the synthetic aperture focusing. In order to determine the optimal sub-aperture size, the formula is derived for calculating the internal sound pressure of the ring array with a 200 mm diameter, and the sound pressure distribution is analyzed. The ring array with 1024 elements (1024 ring array) is established in COMSOL Multiphysics 5.6, and the optimal sub-aperture size is 16 elements, according to the sound field beam simulation and the directivity research. Based on the existing experimental conditions, the ring array with 256 elements (256 ring array) is simulated and verified by experiments. The simulation has a spatial resolution evaluation in the k-Wave toolbox, and the experiment uses nylon rope and breast model imaging. The results show that if the sub-aperture size has four elements, the imaging quality is the highest. Specifically, the spatial resolution is the best, and the sound pressure amplitude and signal-to-noise ratio (SNR) are maintained at a high level in the reconstructed image. The optimal sub-aperture theory is verified by the two kinds of ring arrays, which also provide a theoretical basis for the application of the multi-element synthetic aperture focusing technology (M-SAF) in ring arrays.

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