Stone phantoms were fully immerged with saline solution at ambient temperature and fixed into a bench model. The laser fiber tip was placed perpendicularly and in contact with the surface of the stone. A specific fiber support was manufactured in order to assure the permanent contact with the artificial stone during laser emission (Figure 1 ). First, a two seconds-firing was executed without displacement, in order to determine the static ablation rate. Then, a robotic six-axes arm (KR6R900, Kuka International©, Augsbourg, Germany) was used to realize multiple linear trajectories: 5 mm, 10 mm and 20 mm, maintaining a displacement duration of two seconds. The laser emission and the robotic arm were initiated and stopped jointly by computational command. All experiments were repeated four times. After laser emission, stones were dried as described above.
To assess the ablation volumes, a three-dimensional scanning (micro-CT Quantum FX, Perkin Elmer©, Waltham, MA, USA) of the artificial stones and subsequent 3D segmentation using 3DSlicer software (NIH©) was used (Figure 2 ) [4 (link),14 (link),15 (link)].
To assess the ablation volumes, a three-dimensional scanning (micro-CT Quantum FX, Perkin Elmer©, Waltham, MA, USA) of the artificial stones and subsequent 3D segmentation using 3DSlicer software (NIH©) was used (