Optically tracked multi-robot system for keyhole neurosurgery

Robotic systems have been introduced in surgery to increase the intervention accuracy. In this framework, the ROBOCAST system is an optically controlled multi-robot chain aimed at enhancing the accuracy of surgical probe insertion during keyhole neurosurgery procedures. The system is composed by three robots, connected as a multiple kinematic chain (serial, parallel and linear) totaling 13 degrees of freedom (DoFs) and is it is used to automatically align the probe onto the desired trajectory. This paper presents an iterative approach for aligning the surgical probe with the planned target pose, reducing both the translation and the rotation errors. An experimental protocol was designed, in order to assess the system performances in terms of residual targeting errors and convergence ratio. The proposed targeting procedures allows obtaining (0.06 ± 0.02) mm and (0.8 ± 0.2) × 10^-3 rad as residual median errors, thus satisfying the operational requirements (1 mm). The performances proved to be independent upon the robots calibration accuracy.