Planning and simulation of microsurgical laser bone ablation.

Purpose: Laser ablation of hard tissue is not completely understood until now and not modeled for computer-assisted microsurgery. A precise planning and simulation is an essential step toward the usage of microsurgical laser bone ablation in the operating room.

Methods: Planning the volume for laser bone ablation is based on geometrical definitions. Shape and volume of the removed bone by single laser pulses were measured with a confocal microscope for modeling the microsurgical ablation. To remove the planned volume and to achieve smooth surfaces, a simulation of the laser pulse distribution is developed.

Results: The confocal measurements show a clear dependency from laser energy and resulting depth. Two-dimensional Gaussian functions are fitting in these craters. Exemplarily three ablation layers were planned, simulated, executed and verified.

Conclusions: To model laser bone ablation in microsurgery the volume and shape of each laser pulse should be known and considered in the process of ablation planning and simulation.