B. System Architecture Three-dimensional surgical navigation software 3D Slicer serves as a user interface with the robot. The navigation software is running on a Linux-based workstation in the scanner’s console room. The system workflow follows a preoperative planning, optical frame registration, targeting and verification. OpenIGTLink [14] is used to exchange control, position, and image data. To perform dynamic global registration between the robot and scanner, a passive tracking the fiducial frame is integrated to the robot as shown in Fig. 3.