Abstract: A method for determining a characteristic axis of a body structure includes generating at least two two-dimensional recordings of an area of the body structure; comparing each of the at least two recordings of the area with a generic model of the area in question, said generic model containing information on the position of the characteristic axis; ascertaining a mapping protocol for mapping the respective generic model onto the respective recording of the area; using the ascertained mapping protocol to map the respective position of the characteristic axis in the respective generic model to obtain the respective position of the characteristic axis in the two-dimensional mapping of the body structure; and using rear projection to determine a three-dimensional position of the characteristic axis from the at least two characteristic axes in the two-dimensional mappings.

Abstract: A method and device for selecting a hip joint prosthetic element from a number of hip joint prosthetic elements, wherein bone and/or cartilage contour data of the pelvis and/or the femur are detected and at least one hip joint prosthetic element is selected based on the detected bone and/or cartilage contour data. The device for selecting at least one hip joint prosthetic element from a number of hip joint prosthetic elements, includes a data detection system for detecting bone and/or cartilage contour data, a computational unit for processing the detected bone and/or cartilage contour data, wherein the computational unit is connected to the data detection system, and a database in which characteristic data of a number of hip joint prosthetic elements are stored. The computational unit selects at least one hip joint prosthetic element from the database in accordance with the detected bone and/or cartilage contour data.

Abstract: A positioning system for placing an implant into a cavity of a bone, comprising a cannulated implant that is substantially smaller in the implanting area than the cavity and a positioning device that can hold the implant in a settable position in the cavity.

Abstract: The invention relates to a reference star adapter and a method of re-calibrating a previously registered body using the reference star adapter. The reference star adapter includes a first fixing element for coupling the reference star adapter to a body, and a second fixing element for coupling the reference star adapter to a plurality of markers. At least one joint is coupled between the first fixing element and the second fixing element, and at least one position detector is operatively coupled to the at least one joint, wherein the at least one position detector provides data describing a position or a geometry of the at least one joint.

Abstract: A tracking device for an intramedullary pin whose spatial position is determined and/or tracked in image-guided surgery, including a reference device at a proximal end of the intramedullary pin and a medical navigation system which locates the reference device and determines the orientation of the intramedullary pin from the proximal end. A deformation detection device detects deformations of the intramedullary pin and communicates the deformations to the navigation system. Also provided is a tracking method for determining or tracking the spatial position of an intramedullary pin in image-guided surgery, and to an intramedullary pin that includes a deformation detection device.

Abstract: A method and apparatus for determining the position of a plane of symmetry of a three-dimensional object from at least two two-dimensional mappings, wherein the mappings are obtained from different directions. At least one characteristic line of the three-dimensional object is determined in one of the two-dimensional mappings, and at least one of the two two-dimensional mappings is morphed. The at least one characteristic line is transferred onto the other two-dimensional mapping, and the characteristic lines from the two-dimensional mappings are back-projected to obtain a three-dimensional curve corresponding to the characteristic lines. A plane of symmetry of the object is ascertained from the course of the three-dimensional curve.

Abstract: A balloon for preparing for and easing human birth, which balloon is located at least partly inside the vagina of the pregnant woman during application, has in the inflated condition an application region (P) between its outer end (A), which is provided with a fitting (1) for a flexible tube, and its vaginal portion with the largest diameter (D); the balloon is conically shaped in its application region (P); the application region (P) is disposed approximately within the middle third of the balloon length between an outer portion (a) and an inner portion (i) of the balloon; the cone angle ? in the application region is 25° or smaller.

Abstract: A method for registering an asymmetrical femur implant having a shaft and a collar includes ascertaining a position of a shaft axis associated with the shaft and ascertaining a position of a collar axis associated with the collar. A device for registering an asymmetrical femur implant connected to at least one reference marker is provided. The device includes a detection device for detecting a spatial position of the at least one reference marker and a database in which a geometry of the asymmetrical femur implant is stored. A processor ascertains the spatial position of the asymmetrical femur implant.

Abstract: A device for determining the aperture angle of a joint includes a detection device for detecting positions of joint components and/or positions of structures connected to or to be connected to the joint and a computational unit for ascertaining the aperture angle of the joint based on the detected positions.