HIGH-SPEED ULTRASOUND VOLUMETRIC IMAGING-SYSTEM .1. TRANSDUCER DESIGN AND BEAM STEERING

Transducer design and phased-array beam steering are developed for a volumetric ultrasound scanner that enables the 3-D visualization of dynamic structures in real time. The geometric principles of phased-array beam steering in azimuth and elevation are derived for a 2-D array transducer. Several two-dimensional (2-D) array designs are analyzed for resolution and main lobe-side lobe ratio by simulation using 2-D fast Fourier transform methods. Fabrication techniques are described for 2-D array transducer. Experimental measurements of pulse-echo point spread responses for 2-D arrays agree with the simulations. Measurements of pulse-echo sensitivity, band-width and crosstalk are included.