Abstract: A method for displaying images in a medical navigation system assisted by x-ray images includes calibrating an x-ray device in the medical navigation system and producing a plurality of two-dimensional x-ray images of a patient using the x-ray device. During the producing step, positions of the x-ray device are determined using the medical navigation system in order to produce positional data. Data associated with the two-dimensional x-ray images is converted into three-dimensional data. The two-dimensional x-ray images, production information corresponding to the two-dimension x-ray images, and the three-dimensional data to the navigation system. At least the two-dimensional x-ray images are displayed on an image output of the medical navigation system.

Abstract: An apparatus for determining a coordinate transformation for mixing an image of a first subject into an X-ray image of a second subject has an arrangement for fastening the apparatus to the second subject, markers that can be acquired by a navigation system, and X-ray-positive marks. The positions and orientations of the markers that can be acquired with the navigation system and the positions and orientations of the X-ray-positive marks relative to one another are thus known, so a coordinate transformation can be determined between a coordinate system allocated to the navigation system and a coordinate system allocated to the X-ray image. Thus an image of the first subject that can be acquired with the navigation system can be mixed into an X-ray image of the second subject.

Abstract: A feedback controller for regulating respiratory gas in a mechanical breathing aid system has a comparator means for periodically generating, in a current breathing cycle, an error signal representing the difference between a value of a gas parameter measured for gas within the system and a target value of the gas parameter, and a control signal generator for processing the error signal in accordance with a control function to generate a control signal usable in the regulation of the respiratory gas. The controller has a variable value integral gain stage which provides an input to an integrator element. An adaption unit determines, for the current breathing cycle an extreme value of the periodically generated error signal and varies the value of the integral gain used in the integral gain stage for a next breathing cycle dependent on a rate of change of the value of the extreme error signal with value of the integral gain.

Abstract: A method for displaying images in a medical navigation system assisted by x-ray images includes calibrating an x-ray device in the medical navigation system and producing a plurality of two-dimensional x-ray images of a patient using the x-ray device. During the producing step, positions of the x-ray device are determined using the medical navigation system in order to produce positional data. Data associated with the two-dimensional x-ray images is converted into three-dimensional data. The two-dimensional x-ray images, production information corresponding to the two-dimension x-ray images, and the three-dimensional data to the navigation system. At least the two-dimensional x-ray images are displayed on an image output of the medical navigation system.

Abstract: An apparatus for determining a coordinate transformation for mixing an image of a first subject into an X-ray image of a second subject has an arrangement for fastening the apparatus to the second subject, markers that can be acquired by a navigation system, and X-ray-positive marks. The positions and orientations of the markers that can be acquired with the navigation system and the positions and orientations of the X-ray-positive marks relative to one another are thus known, so a coordinate transformation can be determined between a coordinate system allocated to the navigation system and a coordinate system allocated to the X-ray image. Thus an image of the first subject that can be acquired with the navigation system can be mixed into an X-ray image of the second subject.