Haptic rendering of drilling process in orthopedic surgical simulation based on the volumetric object

Drilling process is a basic skill used in almost all kinds of orthopedic surgeries. Currently, the virtual reality based surgical simulator is still lacking the realism and fidelity to convincingly challenge the actual operation experience on patient. In this paper, to obtain the balance between the high refresh rate of the haptic computation and the well visual result of the virtual environment, we employ a composite data structure to represent the three dimensional bone model. Furthermore, we make some improvements on the traditional voxmap point shell collision detection algorithm to be adapted to the contact model with frequent topology changes. Finally, a force computation method that can handle inhomogeneous bone material is developed based on the mechanical model. With this method, key features of the force sensation changing in the drilling process could be represented in a smooth way.