Ultrasonic Linear Array Medical Imaging System

Modern ultrasound scanners use large either linear or phased array of piezoelectric transducers. Design principle of electronic beamforming networks thus draws heavily from that of adaptive antenna array. However, the interaction of ultrasound with human tissue appears to be much more complicated than that of the electromagnetic wave. While with Xrays we get a shadow image of the system, with ultrasound complete imaging of different organs of different tissue composition is possible. Main criterion that differentiates the interaction is in the very nature of ultrasound. When ultrasound propagates through human tissue layers it spends longer time because of its comparatively lower velocity. The density, elasticity, sound velocity, specific acoustic impedance, absorption, scattering, and the parameters of non-linearity directly control the amount and characteristics of the back scatter component that is received by the same transmitting transducers. In this paper describing the basic ultrasound linear array imaging system briefly a design of a sixteen-element delay-sum beamformer is presented.