Fig. 3
a The bubble clouds created after 10 s exposure to continuous wave (CW) at 30 V (row 1), after exposure to 200 pulses (3 cycles each) of pulse wave (PW) at 150 V (row 2), exposure to 200 pulses of pulse wave at 150 V followed by 10 s of continuous wave at 30 V in the phantoms (row 3). The different droplet concentrations used were 1.07 × 105/mL, 3.41 × 105/mL, 1.07 × 106/mL, 3.41 × 106/mL, and 1.07 × 107/mL, respectively. b The bubble clouds created after 10 s exposure to continuous wave (row 1), exposure to 200 pulses of pulse wave at 150 V followed by 10 s of continuous wave (row 2). The input voltage of the continuous wave were 20 V, 25 V, 30 V, 35 V, 40 V, and 45 V, respectively. The droplet concentration in the phantom was 3.41 × 105/mL. The scale bar represents 2 mm. c The averaged outline of the bubble clouds created after the exposure to 200 pulses of pulsed wave at 150 V in phantom with droplet concentration of 1.07 × 105/mL, 3.41 × 105/mL, 1.07 × 106/mL, 3.41 × 106/mL, and 1.07 × 107/mL, respectively. d The averaged standard deviation along bubble cloud outline in phantoms with different droplet concentrations after the exposure to 200 pulses of pulse wave at 150 V. e The volume of bubble cloud created in cases of different droplet concentrations after PW and after CW exposure. Colored * and ** represents p ≤ 0.05 and p < 0.01 for significance of difference between the group of this color and the group of the PW treatment