Abstract: The present invention relates to a method for ascertaining the position of the head of a medical instrument in a vascular system, wherein the instrument can be inserted into the vascular system of a body and describes a path at least partially inside the vascular system, and the position of the instrument head is calculated from structural data, length data and the relative position between a reference point and the vascular system, wherein the instrument is guided past the reference point, the structural data represents the structure of the vascular system, and the length data represents the length of the path between the reference point and the instrument head.

Abstract: The present invention relates to a method for determining and/or identifying a change in the position of a part of a body structure relative to a marker device by means of a data processing device, comprising the steps of: providing pre-operative data of the body structure which comprises information concerning the pre-operative position of the part of the body structure relative to the marker device; providing intra-operative data of the body structure which comprises information concerning the intra-operative position of the part of the body structure relative to the marker device; and in order to determine whether a change in position has occurred, automatically determining—on the basis of the pre-operative position of the part and the intra-operative position of the part—whether the position of the pre-operative part differs from the position of the intra-operative part and/or automatically displaying the pre-operative position of the part and the intra-operative position of the part, such that a diffe

Abstract: The patent discloses a method and device for measuring the speed of sound of ultrasound waves used in a sonographic examination of a patient's body structure. Marker devices are attached to an ultrasound probe and to an ultrasound reflecting body structure such that the distance traveled by the ultrasound waves can be determined by a navigation system. Using this distance and the transit time of the ultrasound waves, the measured speed can be calculated. The calculated speed of sound may then be used to accurately scale the ultrasound images.

Abstract: A method and device for detecting and displaying an anatomical patient structure in a region of interest of a movable image detection apparatus such as an ultrasound probe. After the region of interest is defined in a patient coordinate system, movement of the image detection apparatus can be tracked, and the position of the region of interest can be changed or shifted to compensate for the movement of the image detection apparatus.