Abstract: An augmented realty system is disclosed that allows a clinician to create and view a 3D model of structure of interest using an imaging device prior to introduction of a tool designed to interact with that structure. The 3D model of the structure can be viewed by the clinician through a head mounted display (HMD) in its proper position relative to the patient. With the 3D model of the structure in view, the imaging device can be dispensed with, and the clinician can introduce the tool into the procedure. The position of the tool is likewise tracked, and a virtual image of a 3D model of the tool is also viewable through the HMD. With virtual images of both the tool and the structure in view, the clinician can visually verify, or a computer coupled to the HMD can automatically determine, when the tool is proximate to the structure.