Fig. 4 (abstract P41).

The sectional view of (a) pressure field and (b) bubble area after 200 cycles of 20 μs pulses of ultrasound exposure, of which focal pressure is 14.7 MPa andfrequency is 750 kHz. The sectional view of (c) pressure field and (d) bubble area when a 1 mm thick of bubble layer pre-existed. The pressure was represented in dB scaleusing 9.8 MPa as the reference pressure. The white scale bar represents 2 mm