Bone removal is essential in cranial and orthopedic surgery but remains time-consuming and highly operator-dependent. We present Cranibot, a surgeon-in-the-loop robotic platform for precision bone removal that integrates an interactive control scheme with a force–position hybrid controller. The system combines computed tomography-based navigation, a custom end effector with dual six-axis force/torque sensors, and an ergonomic handle for surgeon intent input. We extend the instantaneous task specification using constraints framework to fuse surgeon commands with real-time force regulation, enforcing pose constraints while maintaining safe contact forces. Preliminary validation on ex-vivo skull models and an in-vivo porcine feasibility study yielded an average placement error of 2.6 ± 0.56 mm and an average drilling time of under 30 s. Operator forces remained below 5 N, substantially reducing physical load. These initial results indicate that Cranibot can improve efficiency and lessen operator burden, offering a viable pathway toward clinically deployable collaborative bone-removal surgery.
Duan et al. (2026) studied this question.