Photoacoustic ophthalmoscopy (PAOM) is a high-resolution in vivo imaging modality that is capable of providing specific optical absorption information for the retina. A high-frequency ultrasonic transducer is one of the key components in PAOM, which is in contact with the eyelid through coupling gel during imaging. The ultrasonic transducer plays a crucial role in determining the image quality affected by parameters such as spatial resolution, signal-to-noise ratio, and field of view. In this paper, we present the results of a systematic study on a high-frequency ultrasonic transducer design for PAOM. The design includes piezoelectric material selection, frequency selection, and the fabrication process. Transducers of various designs were successfully applied for capturing images of biological samples in vivo. The performances of these designs are compared and evaluated.
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http://dx.doi.org/10.1117/1.JBO.19.1.016015 | DOI Listing |
Ultrasonics
January 2025
Institut Langevin, ESPCI Paris, Université PSL, CNRS, 1 rue Jussieu, Paris, 75005, France.
Detecting surface contamination on thin thermoformed polymer plates is a critical issue for various industrial applications. Lamb waves offer a promising solution, though their effectiveness is challenged by the strong attenuation and anisotropy of the polymer plates. This issue is addressed in the context of a calcium carbonate (CaCO) layer deposited on a polypropylene (PP) plate.
View Article and Find Full Text PDFHeliyon
July 2024
Centre for Ultrasonic Engineering, Department of Electronic and Electrical Engineering, University of Strathclyde, Glasgow, G1 1XQ, UK.
This study explores the inspection of bolted connections in wind turbines, specifically focusing on the application of Phased Array Ultrasonic Testing (PAUT). The research comprises four sections: Acoustoelastic Constant calibration, high tension investigation on bolts, blind tests on larger bolts, and Finite Element Analysis (FEA) verification. The methodology shows accurate results for stress while the bolt is under operative loads, and produces a clear indication of when it is above these loads and beginning to deform.
View Article and Find Full Text PDFEur 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.
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