Direct numerical simulation of the initial stage of a thermally induced microcavitation in a water-rich biotissue triggered by a nanosecond pulsed laser.

A numerical analysis capable of describing the early stage of a thermal microcavitation process in a water-rich biotissue without avalanche breakdown was developed. The analysis successfully reproduced the laser-induced heating, vapor bubble formation, bubble expansion, and shockwave propagation inside a water-rich biotissue during a thermal microcavitation process. Based on the analysis, it was determined that the evolution of the temperature, pressure, and laser-induced shockwave is dependent on the incident laser energy and laser pulse width. On the other hand, the early stage dynamics of the microcavitation process showed little dependence on the elastic modulus of the biotissue for the laser and tissue conditions studied.