Pulsed TV holography combined with computerized tomography (CT) are used to evaluate the three-dimensional distribution of transient acoustic fields in air. Experiments are performed with an electrical discharge between two electrodes as the sound source. Holograms from several directions of the acoustic field are recorded directly onto a CCD detector by use of a double-pulsed ruby laser as the light source. Phase maps, representing projections of the acoustic field, are evaluated quantitatively from the recorded holograms. The projections are used for the CT reconstruction to evaluate the pressure-field distribution in any cross section of the measured volume of air.
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http://dx.doi.org/10.1364/ao.37.000834 | DOI Listing |
Theranostics
January 2025
Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC, USA.
Ultrasound-induced thermal strain imaging (US-TSI) is a promising ultrasound imaging modality that has been demonstrated in preclinical studies to identify a lipid-rich necrotic core of an atherosclerotic plaque. However, human physiological motion, e.g.
View Article and Find Full Text PDFBiomed Phys Eng Express
January 2025
Department of Health Science and Technology, Aalborg University, Selma Lagerløfs Vej 249, Aalborg, 9260, DENMARK.
Unlabelled: Fetal phonocardiography is a well-known auscultation technique for evaluation of fetal health. However, murmurs that are synchronous with the maternal heartbeat can often be heard while listening to fetal heart sounds. Maternal placental murmurs (MPM) could be used to detect maternal cardiovascular and placental abnormalities, but the recorded MPMs are often contaminated by ambient interference and noise.
View Article and Find Full Text PDFChildren (Basel)
November 2024
Faculty of Medical Sciences, State University of Campinas, Campinas 13083-887, SP, Brazil.
Unlabelled: COVID-19 is an infectious disease caused by the SARS-CoV-2 virus. During and after COVID-19, audiovestibular symptoms and impairments have been reported.
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J Acoust Soc Am
January 2025
Escola Politécnica, University of São Paulo, São Paulo, 05508-030, Brazil.
Ultrasonic sensors based on backscattering principles have been developed for various applications involving arbitrary or random scatterer distributions. Although the theory of multiple scattering of waves is well-established, it has not been thoroughly explored in these applications. This work presents a feasible and simplified three-dimensional scattering model to predict the transient response generated by a set of rods positioned in the near field of a 1 MHz water-coupled ultrasonic transducer.
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December 2024
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, CNY 149, 13th St, Charlestown, MA, 02129, USA.
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