Parallel Haptic Rendering for Orthopedic Surgery Simulators

This study introduces a haptic rendering algorithm for simulating surgical bone machining operations. The proposed algorithm is a new variant of the voxmap point-shell method, where the bone and surgical tool geometries are represented by voxels and points, respectively. The algorithm encompasses computationally efficient methods in a data-parallel framework to rapidly query intersecting voxel-point pairs, remove intersected bone voxels to replicate bone removal and compute elemental cutting forces. A new force model is adopted from the composite machining literature to calculate the elemental forces with higher accuracy. The integration of the algorithm with graphic rendering for visuo-haptic simulations is also outlined. The algorithm is benchmarked against state-of-the-art methods and is validated against prior experimental data collected during bone drilling and glenoid reaming trials. The results indicate improvements in computational efficiency and the force/torque prediction accuracy compared to the existing methods, which can be ultimately translated into higher realism in simulating orthopedic procedures.