The Virtual Reality Center Aachen is developing a Virtual Reality based operation planning system in cooperation with
aerodynamics scientists and physicians of several clinical centers. This system is meant to help the preparation of nose
surgeries aimed at the elimination of respiratory diseases. A core part is the interactive comparison of experimental data
and simulation data in the area of fluid dynamics. In a first step, data comparison is to depict the differences between
healthy noses and diseased noses. Later on, data comparison should supply evidence for successful virtual surgeries,
which finally results in guidance on the real operation.
During virtual surgery sessions, scientists can interactively explore, analyze, annotate, and compare various medical and
aerodynamics data sets. Image-based methods are used to extract several features in one image and between compared
data sets. The determination of linked features between different data sets is a particular challenge because of their
different time frames, scales, and distortions. An optimized human computer interface enables the user to interact
intuitively within a virtual environment in order to select and deal with these data sets. Additionally to this interactive
exploration, the system also allows automatic searches for cut plane and key frame candidates corresponding to given
The comparison system makes use of an already implemented parallelized Computational Fluid Dynamics (CFD) postprocessing,
which also extracts enhanced flow features that allow automatic detection of relevant flow regions. Beside
vortex detection, the computation of critical points including flow field segmentation is a current research activity.
These flow features are favored characteristics for the comparison and help considerably to classify different nose
geometries and operation recommendations.