<title>Design guidelines for medical ultrasonic arrays</title>

Abstract

The basics ofultrasomc transducer array design in the frequency range useful for medical imaging ( 1-10 MHz) are discussed. Performance parameters of importance in transducer design are considered, including sensitivity, coupling constant, band width, frequency downshift, pulse duration, beam focusing properties, and electrical matching. Two and three dimensional effects must also be taken into account. The advantages of computer modeling in three dimensions with finite element analysis code are highlighted. The principles of multi-element array transducers useful for two dimensional real-time scanning are reviewed. Two dimensional arrays provide the opportunity offocusing the elevation beam dimension in the short axis, or make possible full three dimensional scanning volumes.

Low acoustic attenuation silicone rubber lens for medical ultrasonic array probe

“…First, the radius of curvature for the acoustic lens becomes large as the sound speed of the acoustic lens becomes low. second, the thickness of the acoustic lens becomes thin as the radius of the lens becomes large in the case of the same aperture size [8], [9]. In short, the thickness of the acoustic lens decreases as the sound speed of the acoustic lens becomes low.…”

An optimized ultrasound detector for photoacoustic breast tomography

“…The theoretical values for the suitable acoustic impedance of the matching layers (Z m ) can be determined by [35,38]:…”

The acoustic lens design and in vivo use of a multifunctional catheter combining intracardiac ultrasound imaging and electrophysiology sensing

“…The classical lens formula that is usually used to control first-order elevation beam performance does not help very much because it is applied typically with a very large lens radius for subtle phase adjustments to the native beam. The standard lens formula [27], (1) where daf is the depth-at-focus, roc is the radius of lens curvature, and V lens and V med are the acoustic velocities of the lens and medium, respectively, can be useful for finding the radius of curvature needed with a large radius and slow lens material. The relation is derived by assuming that the geometric angles are small, i.e., that sin(θ) ~ θ, where θ is the angle, with apex at the center of lens curvature, between the beam centerline and a point on the surface of the lens.…”