Abstract: The invention relates to a calibration method for an axially determinate medical instrument, wherein: the instrument, which is situated within the localization range of a medical tracking system, is positioned such that it can be rotated about its spatially fixed or spatially determinate axis; the instrument is rotated about the axis, wherein a reference which is situated on the instrument or is arranged on and/or fastened to the instrument such that it is spatially fixed relative to the instrument comes to rest at at least two positions; the at least two positions are spatially determined with the aid of the tracking system; the axis of the instrument is spatially determined from the determined positions; and wherein the axis thus determined is assigned to the tracked instrument.

Abstract: A medical instrument having a handle and a functional portion includes a first part, a second part selectively couplable to the first part and a plurality of trackable markers arranged on the instrument. At least one marker is arranged on the first part and at least one marker is arranged on the second part.