This paper presents a theoretical model of the dynamics of liquid flow in an angular accelerometer comprising a porous transducer in a circular tube of liquid. Wave speed and dynamic permeability of the transducer are considered to describe the relation between angular acceleration and the differential pressure on the transducer. The permeability and streaming potential coupling coefficient of ...

BACKGROUND Recommended phantom-based quality assurance measurements in B-mode ultrasound (US) may be tedious. For the purpose of cost-effective US quality assurance it is important to evaluate measurements that effectively reflect the quality of US scanner. PURPOSE To find out which recommended phantom-based quality assurance measurements are effective in detecting dead or weak transducer ele...

Doppler sonographic measurement of flow velocity in the basal cerebral arteries through the intact skull was developed using a pulsed Doppler technique and 2 MHz emitting frequency. Relaxor-based ferroelectric single crystals Pb(Mg1/3Nb2/3)O3-PbTiO3 (PMN-PT) were chosen to be the piezoelectric transducer material due to their ultrahigh piezoelectric coefficients, high electromechanical coupling...

The cavitation field in a cylindrical vessel bottom-insonified by a 19.7kHz large area transducer is studied experimentally. By adding controlled amounts of Poly-Ethylene Glycol (PEG) to water, the viscosity of the liquid is varied between one- and nine-fold the viscosity of pure water. For each liquid, and for various displacement amplitudes of the transducer, the liquid is imaged by a high-sp...

The acousto-optic effect, in which an acoustic wave causes variations in the optical index of refraction, imposes a fundamental limitation on the determination of the normal velocity, or normal displacement, distribution on the surface of an acoustic transducer or optically reflecting pellicle by a scanning heterodyne, or homodyne, laser interferometer. A general method of compensation is devel...

This paper presents an ultrasonic transducer modeling with VHDL-AMS standard (Very High speed integrated circuits Hardware Description Language – Analog and Mixed Signal) referenced IEEE 1076.1, integrated in a global measurement cell modeling dedicated to biological tissues ultrasound characterization. Usual modeling of ultrasonic transducer are based on electrical analogy and are not simulate...

ABSTRACT Spherical microphone arrays(SMAs) were widely used in sound field recording, beamforming,etc. for its advantage of high geometrical symmetry. Many factors could affect the performance of SMAs, including transducer errors. In this paper, effect of transducer mismatch in amplitude and phase on the performance of SMAs was studied through simulation calculation. A SMAs with 64 nearly unifo...

This paper outlines a mathematical framework to determine the upper bound on extractable power as a function of the forcing vibrations. In addition, the method described provides insight into the dynamic transducer forces required to attain the upper bound. The relationship between vibration parameters and transducer force gives a critical first step in determining the optimal transducer archit...

Real-time three-dimensional (3D) high-resolution ultrasound imaging requires 2D phased arrays operating at frequencies higher than 50 MHz, which poses a great challenge for piezoelectric technologies. A promising alternative is an optoacoustic array relying on optical generation and detection of ultrasound. We present an all-optical ultrasound transducer, which consists of a 2D gold nanostructu...

Background Intraoperative epicardial coronary Doppler ultrasound has the potential to provide anatomic and functional information. This technique has been hindered by the large size of standard transducers, but a miniature transducer is available that may fulfill the potential of coronary ultrasound. Methods and Results Twenty consecutive patients who were undergoing coronary artery bypass graf...