Figure 2.

Experimental setup for optical tracking in vivo. A: A model of the physical set up of the optically tracked NHP neuromodulation experiment. The NHP was placed on a custom table for MR imaging with its head fixed in place using a stereotactic frame built into the NHP table. The FUS transducer was placed over the head on a frame built into the table. The transducer has an optical tracker placed on the back and a water bubble for ultrasound coupling. Fiducials were placed on the ear bars and eye bars of the frame (red spheres). A reference tracker was fixed to the table for optical tracking. MR coils were placed on either side of the head (not pictured). The black dashed region was the approximate MR imaging region in B. B: The 3D Slicer view of the NHP experiment. The optically tracked focus model is shown with the green cylinder. Fiducial markers (red spheres) were localized and registered to the physical marker locations. The individual elements of the transducer were visualized in the MR space.