Haptic simulation of bone drilling based on hybrid 3D part representation

Bone drilling is a common and highly skilled process of many surgical procedures. In this paper, a new method for six degrees of freedom (DOF) haptic rendering of thrust force and torques is proposed and implemented for the simulation of bone drilling. In the proposed method, a bone is represented as a hybrid of mesh and voxel model. When the drill bit comes into contact with the mesh model of a bone, a cylindrical volumetric model along the drill axis is generated automatically. The cylindrical volumetric model (represented as voxel) is made static when the drill bit has penetrated the bone with a pre-defined depth. By doing this, both haptic rendering and graphic rendering of the drilling process is localized to the small cylindrical model. This can significantly improve the haptic rendering efficiency. Given a volumetric model, both thrust force and torque in roll are modeled based on material removal rate. To demonstrate the fidelity, a prototype bone drilling simulation system is developed using a 6 degree-of-freedom (DoF) haptic device.