A 2-DOFs Planar Grinding End-Effector for Robotic Laminectomy

Robotic end effector accurately operated in small and confined surgical area in laminectomy can improve the efficiency of robotic surgery. This paper proposed a two-DOFs planar grinding end-effector for robotic laminectomy, which can move along any curve within the planar operation area. The end-effector adopts an arc RCM mechanism, which kinematic analysis gives a working space of an annular sector with a minimum radius of 137 mm, a maximum radius of 162.3 mm, a central angle of 1.65 rad. The structure rationality of the end-effector is verified through static analysis. The prototype was developed and controlled based on TwinCAT-PC architecture. Experiments of positioning accuracy give a repeated positioning accuracy of 0.1 mm. Experiments of ex vivo bone grinding gives an operation accuracy of 1.5 mm in a simulated clinical environment. The proposed prototype can be used for robotic laminectomy in combination with the navigation robotic arm.