Abstract: The invention relates to a navigation system for guiding a catheter in a patient's vascular system, where the spatial position of the catheter and its orientation are continually measured by a locating device. The resulting trajectory (T0) of the catheter contains movement artefacts on account of the heartbeat. In order to suppress said movement artefacts, the electrocardiogram (ECG) is recorded in parallel, and the position and orientation signals are suppressed during phases of strong heart movement (QRS peak). Preferably, extrapolation of the compensated trajectory (Tc) is carried out in the gaps arising as a result of signal suppression.

Abstract: The invention relates to an apparatus and a method for recording the movement, caused in particular by breathing, of organs of the body such as the heart (9) for example. A part (3) of the diaphragm (10) is recorded by means of an X-ray device or an ultrasound device and the current position of the diaphragm is detected in the resulting image. Information about the associated position of other internal organs can be obtained from the position of the diaphragm with the aid of a model. This information can in turn be used, in a navigation system for a catheter, to set the spatial coordinates of the latter relative to the vascular system.

Abstract: The invention relates to a method of segmenting a three-dimensional structure from a three-dimensional, and in particular medical, data set while making allowance for user corrections. The method is performed with the help of a deformable three-dimensional model whose surface is formed by a network of nodes and mashes that connect these nodes. Once the model has been positioned at the point in the three-dimensional data set at which the structure to be segmented is situated and positions of nodes have, if necessary, been changed by known methods of segmentation, any desired nodes can be displaced manually. The nodes of the model are recalculated by making weighted allowance for the nodes that have been displaced manually.