This rectilinear orthogonial instrument consisted of a heavy frame and fixation pins. Two lateral grids for alignment of the x-ray beam were placed at a distance from the frame to reduce distortion. Internal brain structures of the temporal lobe were used to localize the targets. Initially used to biopsy brain tumors and introduce radioactive isotopes, it was later employed to introduce depth electrodes in the temporal lobe of epileptic patients.
Reference:
Talairach, J. and de Ajuriaguerra, J. and David, M. Etudes stereotactiques des structure encephaliques profondes chez l'homme techniques. Presse Med. 1952 60(28): 605-609.