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The characteristics of hearing aids should be determined and regulated to ensure patient safety and to optimize the performance of the hearing aids. The objectives of this work were to design and develop a hearing aid measurement system to obtain the performance characteristics of the hearing aids. The implementation of this work is based on the method recommended in the International Electrotechnical...
During the past decade, signals from conventional focusing schemes with one or a few focal depths have been used in ultrasound elastography. Echo signals from transducer elements have been delayed and summed coherently only at the focus depths, therefore, elastograms reconstructed from these signals could have limited resolution at the area far away from the focal depths. In this work, dynamic focusing...
Many ultrasound elastograms are reconstructed from pre- and post-compression radiofrequency (RF) signals after beamforming using a single or a few focusing depths. This might limit the accuracy of the displacement estimates for elastography in the area far from the focusing depths. This article studies the improvement of the elastograms reconstructed from the signals beamformed using a dynamic focusing...
The primary objective of this work was to develop and optimize the calibration techniques for ultrasonic hydrophone probes used in acoustic field measurements up to 100MHz. A dependable, 100MHz calibration method was necessary to examine the behavior of a sub-millimeter spatial resolution fiber optic (FO) sensor and assess the need for such a sensor as an alternative tool for high frequency characterization...
Broadband fiber optic hydrophones are an attractive solution for characterization and measurement of high intensity acoustic fields which are encountered in clinical ultrasound applications upto 100 MHz. A small sensing area avoids spatial acoustic field averaging and provides sub-millimeter resolution required for enhanced imaging in diagnostic applications. In this paper we present analytical and...
The primary objective of this research was to develop and optimize the calibration techniques for ultrasonic hydrophone probes in acoustic field measurements up to 100 MHz. Dependable, 100 MHz calibration method was necessary to examine behavior of the sub-millimeter fiber optic (FO) sensor and assess the need for such a sensor as an alternative tool for high frequency characterization of ultrasound...
A broadband fiber-based hydrophone probe is reported for measurements of high frequency (up to 100 MHz) ultrasonic fields. The fiber probe with a tip diameter on the order of about 9 microns provides an effective measurement tool, which is adequate for mm spatial resolution and they could eliminate the need for spatial averaging corrections. Power budget calculation of the fiber sensor has been performed,...
This work describes the results of initial evaluation of a wideband acousto-optic hydrophone probe designed to operate as point receiver in the frequency range up to 100MHz. The hydrophone was implemented as a tapered fiber optic (FO) probe sensor with a tip diameter of approximately 7μm. Such small physical dimensions of the sensor eliminate the need for spatial averaging corrections so that true...
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