Fig. 2.

(a) The 4Z1C imaging transducer inserted into the central opening of the HIFU piston and rigidly fixed with the holder. (b) System block diagram of the experimental setup used for tracking radiation force induced shear wave propagation in 3D. The shear wave is generated with the HIFU piston, and tracked using the 4Z1C matrix array. The two transducers are synchronized by the line sync signal from the SC2000, which provides precise timing of transmit events on the 4Z1C. When the appropriate number of transmits have occurred, the triggering circuit causes the signal generator to emit a 1.1MHz burst of selected amplitude and duration (200–400 cycles). This signal is amplified by 55 dB by an RF power amplifier (E&I A150, Electronics & Innovation, Rochester, NY), and goes through an impedance matching network, before finally driving the HIFU piston to generate the acoustic radiation force push.