Fig. 6.
Cavitation bubble clouds during histotripsy treatment of swelled and non-swelled synthetic hydrogels and corresponding agarose hydrogel controls. Hydrogels were synthesized in the agarose resection phantoms and subjected to histotripsy treatment immediately (non-swelled) or submerged in 1X PBS at 37 °C for 24 h prior to treatment (swelled). For all treatments, 100 histotripsy pulses were applied at 0.5 Hz PRF with a 500 kHz transducer. Cured agarose hydrogels (as formed) and agarose hydrogels submerged in 1X PBS at 37 °C for 24 h (hydrated) were used as the corresponding control group for cavitation threshold studies. Focused ultrasound waves are being transmitted from right to left. A Representative cavitation bubble cloud images in hydrogels taken from the 50th pulse at various peak negative pressures. B Representative cavitation bubble cloud images in hydrogels from a range of pulses at 49.9 MPa. Scale bars are 1 mm.