Digital Filtering of Acoustic Images

We describe in this paper the use of various types of filtering techniques to improve the resolution of a Varian V3000 real-time ultrasonic imaging system. This system, which operates at 2.25 MHz center frequency, employs a 32-element imaging array 1.28 cm wide. Thirty-two elements are used on transmit and the central sixteen elements on receive. After envelope detection, the image intensity obtained is stored in a solid state RAM and is available for digital processing, as shown in Fig. 1.