The Characteristics of the Behavior of Impact Energy and Treatment for Urolithiasis by Holmium:YAG Laser

Abstract

We conducted objective observations and compared the crushing effects of engineered energy caused by laser radiation according to the irradiation distance to the target as well as the irradiation direction. Observations were carried out in a water bath and the behavior from bubble formation to collapse was observed with a high-speed video camera synchronized with the impact at bubble collapse. Observations of the behavior and impact energy of induced bubbles in the vicinity of the wall clearly indicated that there is an optimal irradiation distance from the target and that it differs depending on the irradiation direction. Experiments were carried out with fibers placed parallel or perpendicular to the solid wall surface. We found that the acquisition of effective energy by laser irradiation has different characteristics depending on the irradiation direction and irradiation environment, and that it is possible to acquire effective energy and avoid influencing the peripheral tissues by adapting the irradiation style to various situations.