Miniature histotripsy device to treat human pathologies

A high-frequency (6 MHz), miniature histotripsy device was developed to treat human pathologies using bubble-based focused ultrasound therapy to mechanically ablate tissue. The goal of this study was to determine the effect of pulses per treatment point on bubble formation and subsequent tissue ablation area using tissue-mimicking phantoms. These phantoms were designed to closely simulate the mechanical and acoustic properties of human tissues. Fibrinogen and thrombin, along with 5% fetal bovine serum, were added to form a fibrin gel incubated at 37 °C for 1 h to ensure fibrin formation. Subsequently, human MC38 cells were co-cultured with the fibrin gel for at least 1 day prior to treatment. Histotripsy pulses above the cavitation threshold were applied ranging from 500 to 5000 pulses. Bubble formation and dynamics were monitored in real-time using ultrasound imaging to detect the extent of ablation and was compared to post hoc optic imaging. The results indicated that the number of pulses applied, and ultrasound pressure influenced bubble dynamics, which in turn affected the ablation area. Increased number of pulses applied was correlated with larger ablation areas, highlighting the importance of optimizing bubble detection under real-time imaging to maximize histotripsy treatment efficacy.