Fig. 4.

Stereotactic methods and co-registration for target attainment: (a) Image of Leksell D stereotactic frame. (b) Final head-fixation frame with fiducial arc and MRI visible balls. (c) Image of immobilised pig under the Pathfinder surgical robotic arm: end effector location is arrowed. Note the replacement of optical reflector balls around the fiducial arc to aid robot/head-frame co-registration. (d) Image illustrating robot end effector used for the delivery of stiff cannula to targets in the brain.