TY - GEN A1 - Hege, Hans-Christian A1 - Seebass, Martin A1 - Stalling, Detlev A1 - Zöckler, Malte T1 - A Generalized Marching Cubes Algorithm Based on Non-Binary Classifications N2 - We present a new technique for generating surface meshes from a uniform set of discrete samples. Our method extends the well-known marching cubes algorithm used for computing polygonal isosurfaces. While in marching cubes each vertex of a cubic grid cell is binary classified as lying above or below an isosurface, in our approach an arbitrary number of vertex classes can be specified. Consequently the resulting surfaces consist of patches separating volumes of two different classes each. Similar to the marching cubes algorithm all grid cells are traversed and classified according to the number of different vertex classes involved and their arrangement. The solution for each configuration is computed based on a model that assigns probabilities to the vertices and interpolates them. We introduce an automatic method to find a triangulation which approximates the boundary surfaces - implicitly given by our model - in a topological correct way. Look-up tables guarantee a high performance of the algorithm. In medical applications our method can be used to extract surfaces from a 3D segmentation of tomographic images into multiple tissue types. The resulting surfaces are well suited for subsequent volumetric mesh generation, which is needed for simulation as well as visualization tasks. The proposed algorithm provides a robust and unique solution, avoiding ambiguities occuring in other methods. The method is of great significance in modeling and animation too, where it can be used for polygonalization of non-manifold implicit surfaces. T3 - ZIB-Report - SC-97-05 Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-2741 ER - TY - GEN A1 - Deuflhard, Peter A1 - Seebass, Martin A1 - Stalling, Detlev A1 - Beck, Rudolf A1 - Hege, Hans-Christian T1 - Hyperthermia Treatment Planning in Clinical Cancer Therapy: Modelling, Simulation and Visualization N2 - \noindent The speaker and his co-workers in Scientific Computing and Visualization have established a close cooperation with medical doctors at the Rudolf--Virchow--Klinikum of the Humboldt University in Berlin on the topic of regional hyperthermia. In order to permit a patient--specific treatment planning, a special software system ({\sf\small HyperPlan}) has been developed. \noindent A mathematical model of the clinical system ({\it radio frequency applicator with 8 antennas, water bolus, individual patient body}) involves Maxwell's equations in inhomogeneous media and a so--called bio--heat transfer PDE describing the temperature distribution in the human body. The electromagnetic field and the thermal phenomena need to be computed at a speed suitable for the clinical environment. An individual geometric patient model is generated as a quite complicated tetrahedral ``coarse'' grid (several thousands of nodes). Both Maxwell's equations and the bio--heat transfer equation are solved on that 3D--grid by means of {\em adaptive} multilevel finite element methods, which automatically refine the grid where necessary in view of the required accuracy. Finally optimal antenna parameters for the applicator are determined . \noindent All steps of the planning process are supported by powerful visualization methods. Medical images, contours, grids, simulated electromagnetic fields and temperature distributions can be displayed in combination. A number of new algorithms and techniques had to be developed and implemented. Special emphasis has been put on advanced 3D interaction methods and user interface issues. T3 - ZIB-Report - SC-97-26 Y1 - 1997 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-2958 ER - TY - CHAP A1 - Beck, Rudolf A1 - Deuflhard, Peter A1 - Hege, Hans-Christian A1 - Seebass, Martin A1 - Stalling, Detlev ED - Hege, Hans-Christian ED - Polthier, Konrad T1 - Numerical Algorithms and Visualization in Medical Treament Planning T2 - Visualization and Mathematics Y1 - 1997 SP - 303 EP - 328 PB - Springer-Verlag ER - TY - CHAP A1 - Nadobny, Johanna A1 - Wust, Peter A1 - Seebass, Martin A1 - Stalling, Detlev A1 - Hege, Hans-Christian A1 - Deuflhard, Peter A1 - Felix, Roland T1 - A Quantitative Comparison between the VSIE and the FDTD method using Electrically Equivalent Patient and Antenna Models T2 - Proc. 16th Ann. Meeting Europ. Soc. Hyperthermic Oncology (ESHO-97), Berlin, Germany, April 1997 Y1 - 1997 SP - 145 ER - TY - CHAP A1 - Deuflhard, Peter A1 - Seebass, Martin A1 - Stalling, Detlev A1 - Beck, Rudolf A1 - Hege, Hans-Christian ED - Sydow, Achim T1 - Hyperthermia Treatment Planning in Clinical Cancer Therapy:Modelling, Simulation, and Visualization T2 - Computational Physics, Chemistry and Biology Y1 - 1997 VL - 3 PB - Wissenschaft und Technik Verlag CY - Plenary keynote talk, 15th IMACS World Congress 1997 on Scientific Computation, Modelling and Applied Mathematics ER - TY - CHAP A1 - Seebaß, Martin A1 - Stalling, Detlev A1 - Zöckler, Malte A1 - Hege, Hans-Christian A1 - Wust, Peter A1 - Felix, Roland A1 - Deuflhard, Peter T1 - Surface Mesh Generation for Numerical Simulations of Hyperthermia Treatments T2 - Proceedings of the 16th Annual Meeting of the European Society for Hyperthermic Oncology (ESHO-97) Y1 - 1997 SP - 146 ER - TY - CHAP A1 - Deuflhard, Peter A1 - Seebaß, Martin A1 - Stalling, Detlev A1 - Beck, Rudolf A1 - Hege, Hans-Christian ED - Sydow, Achim T1 - Hyperthermia Treatment Planning in Clinical Therapy T2 - Computational Physics, Chemistry and Biology (Proceedings of the 15th IMACS World Congress 1997 on Scientific Computation 3, Modelling and Applied Mathematics) Y1 - 1997 SP - 9 EP - 17 PB - Wissenschaft und Technik Verlag ER - TY - CHAP A1 - Wust, Peter A1 - Nadobny, Jacek A1 - Gellermann, Johanna A1 - Seebaß, Martin A1 - Stalling, Detlev A1 - Hege, Hans-Christian A1 - Deuflhard, Peter A1 - Felix, Roland T1 - Patient Models and Algorithms for Hyperthermia Planning T2 - Proceedings of the 16th Annual Meeting of the European Society for Hyperthermic Oncology ESHO-97 Y1 - 1997 ER - TY - CHAP A1 - Seebass, Martin A1 - Stalling, Detlev A1 - Zöckler, M. A1 - Hege, Hans-Christian A1 - Wust, Peter A1 - Felix, Roland A1 - Deuflhard, Peter T1 - Surface Mesh Generation for Numerical Simulations of Hyperthermia Treatments T2 - Proc. 16th Ann. Meeting Europ. Soc. Hyperthermic Oncology (ESHO-97), Berlin, Germany, April 1997 Y1 - 1997 SP - 146 ER - TY - CHAP A1 - Wust, Peter A1 - Nadobny, Johanna A1 - Gellermann, Johanna A1 - Seebass, Martin A1 - Stalling, Detlev A1 - Hege, Hans-Christian A1 - Deuflhard, Peter A1 - Budach, Volker A1 - Felix, Roland T1 - Patient Models and Algorithms for Hyperthermia Planning T2 - Proc. 16th Ann. Meeting Europ. Soc. Hyperthermic Oncology (ESHO-97), Berlin, Germany, April 1997 Y1 - 1997 SP - 75 ER -