The present embodiments relate to a method for determining a unique spatial relation of a medical device to an object. The medical device includes a registration mechanism with a first determination of the spatial relation of the medical device to the object by the registration mechanism by a first method for determining a relation of this kind, and with a second determination of the spatial relation of the medical device to the object by the registration mechanism by a second method for determining a relation of this kind. The second method is based on a physical principle of action different from that of the first method, with an evaluation of the results of the first and second determinations with respect to conformance by the registration mechanism, and, on the determination of a prespecified degree of conformance between the results, with a final determination of the spatial relation from the results of the first and second determinations by the registration mechanism to increase the safety of the medical device during operation in spatial interaction with a object.
