Predicting the growth of nanoscale nuclei by histotripsy pulses

Histotripsy is a focused ultrasound therapy that ablates tissue through the mechanical action of cavitation. Histotripsy-initiated cavitation activity is generated from shocked ultrasound pulses that scatter from incidental nuclei (shock scattering histotripsy), or purely tensile ultrasound pulses (microtripsy). The Yang/Church model was numerically integrated to predict the behavior of the cavitation nuclei exposed to measured shock scattering histotripsy pulses. The bubble motion exhibited expansion only behavior, suggesting that the ablative action of a histotripsy pulse is related to the maximum size of the bubble. The analytic model of Holland and Apfel was extended to predict the maximum size of cavitation nuclei for both shock scattering histotripsy and microtripsy excitations. The predictions of the analytic model and the numerical model agree within 2% for fully developed shock scattering histotripsy pulses (>72 MPa peak positive pressure). For shock scattering histotripsy pulses that are not fully developed (