A non-linear control method, known as Variable Structure Control (VSC), is employed to reduce the duration of ultrasonic (US) transducer transients. A physically realizable system using a simplified form of the VSC algorithm is proposed for standard piezoelectric transducers and simulated. Results indicate a VSC-controlled transmitter reduces the transient duration to less than a carrier wave cycle. Applications include high capacity ultrasound communication and localization systems.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.ultras.2013.07.017 | DOI Listing |
Eur Radiol
January 2025
Department of Information Technology, Uppsala University, 75237, Uppsala, Sweden.
Objectives: The aim is to assess the feasibility and accuracy of a novel quantitative ultrasound (US) method based on global speed-of-sound (g-SoS) measurement using conventional US machines, for breast density assessment in comparison to mammographic ACR (m-ACR) categories.
Materials And Methods: In a prospective study, g-SoS was assessed in the upper-outer breast quadrant of 100 women, with 92 of them also having m-ACR assessed by two radiologists across the entire breast. For g-SoS, ultrasonic waves were transmitted from varying transducer locations and the image misalignments between these were then related analytically to breast SoS.
Ultrasonics
January 2025
Department of Civil Engineering and Architecture, Tallinn University of Technology, Ehitajate tee 5, 19086, Tallinn, Estonia. Electronic address:
Pipe bends are recognized as critical areas susceptible to wall thinning, a phenomenon instigated by abrupt changes in the fluid flow direction and velocity. Conventional monitoring techniques for bends typically depend on localized ultrasonic measurements of thickness. While these methods are effective, they can be time-consuming compared to the use of permanently installed transducers, a strategy employed in guided wave tomography (GWT).
View Article and Find Full Text PDFSensors (Basel)
December 2024
School of Instrument and Electronics, North University of China, Taiyuan 030051, China.
Tire pressure monitoring systems (TPMSs) are essential for maintaining driving safety by continuously monitoring critical tire parameters, such as pressure and temperature, in real time during vehicle operation. Among these parameters, tire pressure is the most significant, necessitating the use of highly precise, cost-effective, and energy-efficient sensing technologies. With the rapid advancements in micro-electro-mechanical system (MEMS) technology, modern automotive sensing and monitoring systems increasingly rely on MEMS sensors due to their compact size, low cost, and low power consumption.
View Article and Find Full Text PDFUltrasonics
January 2025
Department of Biomedical Engineering, The George Washington University, 800 22 nd St. NW Suite 5000, Washington, DC 20052, United States of America. Electronic address:
Objectives: In this study, we aim to investigate whether therapeutic ultrasound can modulate the release of melatonin from the pineal gland-either increasing or decreasing its levels-and to assess the safety of this technique. This research could address a significant clinical need by providing a noninvasive method to potentially regulate sleep and circadian rhythms through the targeted modulation of melatonin.
Methods: Rat pineal glands were placed in a well with a Krebs Ringer Buffer solution.
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.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!