A novel tele-operated flexible surgical arm with optimal trajectory tracking aiming for minimally invasive neurosurgery

Snake-like flexible manipulators (FMs) are very important in minimally invasive surgery (MIS). However, existing solutions lack adequate dexterity as they can only control either the angulation or the length of the bending section. Moreover they cannot “follow the leader”, which is critical in neurosurgeries. This paper intends to provide a design to solve such problems. A novel tele-operated tendon-driven surgical arm system is developed. It includes a constrained tendon-driven serpentine manipulator (CTSM) and the Novint Falcon haptic input device. An optimal trajectory tracking method is proposed for the CTSM. Two modes of tele-operation for the CTSM are implemented. One is direct mapping mode and the other is incremental mode. In the CTSM both the angulation and the length of the bending section are controllable, which endows the CTSM larger workspace and better dexterity than existing counterparts. In the L shape trajectory tracking, the CTSM can nearly “follow the leader”. What´s more the stiffness and stability are optimized in the meantime. The CTSM can be operated in the two modes effectively. The direct mapping mode is well suited for fast moving and the incremental mode provides fine adjustment.