Implant and delivery system for neural stimulator

Apparatus is provided for use with an optical fiber shape-sensing system. The apparatus includes an optical fiber, optically couplable to the optical fiber shape-sensing system, and configured to change shape during advancement through a greater palatine canal of a subject. The apparatus additionally includes a delivery tool configured to be removably coupled to the optical fiber and to distally advance the optical fiber through the greater palatine canal. The apparatus further includes a neural stimulator implant, configured to apply electrical stimulation to a sphenopalatine ganglion (SPG) of the subject. The neural stimulator implant is not in contact with the optical fiber, and is shaped and sized to be delivered to the sphenopalatine ganglion (SPG) by the delivery tool. Other applications are also described.