@inproceedings{NadobnySullivanWustetal.1998, author = {Nadobny, Johanna and Sullivan, Dennis and Wust, Peter and Seebass, Martin and Deuflhard, Peter and Felix, Roland}, title = {A High Resolution Interpretation at Arbitrary Interfaces for the FDTD Method}, series = {IEEE Transactions on Microwave Theory and Techniques}, volume = {46}, booktitle = {IEEE Transactions on Microwave Theory and Techniques}, number = {11}, pages = {1759 -- 1766}, year = {1998}, language = {en} } @article{NadobnySullivanWustetal.1998, author = {Nadobny, Jacek and Sullivan, Dennis and Wust, Peter and Seebaß, Martin and Deuflhard, Peter and Felix, Roland}, title = {A High-Resolution Interpolation at Arbitary Interfaces for the FDTD Method}, series = {IEEE Trans. Microwave Theory Tech.}, volume = {46}, journal = {IEEE Trans. Microwave Theory Tech.}, number = {11}, doi = {10.1109/22.734576}, pages = {1759 -- 1766}, year = {1998}, language = {en} } @misc{DeuflhardWeiserSeebass, author = {Deuflhard, Peter and Weiser, Martin and Seebass, Martin}, title = {A New Nonlinear Elliptic Multilevel FEM Applied to Regional Hyperthermia}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-3785}, number = {SC-98-35}, abstract = {In the clinical cancer therapy of regional hyperthermia nonlinear perfusion effects inside and outside the tumor seem to play a not negligible role. A stationary model of such effects leads to a nonlinear Helmholtz term within an elliptic boundary value problem. The present paper reports about the application of a recently designed adaptive multilevel FEM to this problem. For several 3D virtual patients, nonlinear versus linear model is studied. Moreover, the numerical efficiency of the new algorithm is compared with a former application of an adaptive FEM to the corresponding instationary model PDE.}, language = {en} } @inproceedings{DeuflhardSeebass1998, author = {Deuflhard, Peter and Seebaß, Martin}, title = {Adaptive Multilevel FEM as Decisive Tools in the Clinical Cancer Therapy Hyerthermia}, series = {Proc. Eleventh International Conference on Domain Decomposition Methods in Sciences and Engineering}, booktitle = {Proc. Eleventh International Conference on Domain Decomposition Methods in Sciences and Engineering}, editor = {Lai, Choi-Hong and Bjorstad, Petter and Cross, Mark and Widlund, Olof}, address = {Greenwich, UK}, pages = {410 -- 421}, year = {1998}, language = {en} } @misc{DeuflhardSeebass, author = {Deuflhard, Peter and Seebass, Martin}, title = {Adaptive Multilevel FEM as Decisive Tools in the Clinical Cancer Therapy Hyperthermia}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-3739}, number = {SC-98-30}, abstract = {The paper surveys recent progress in a joint mathematical-medical project on cancer therapy planning. Within so-called regional hyperthermia the computational task is to tune a set of coupled radiofrequency antennas such that a carefully measured tumor is locally heated, but any outside hot spots are avoided. A mathematical model of the whole clinical system -- air, applicator with antennas, water bolus, individual patient body -- involves Maxwell's equations in inhomogeneous media and a parabolic bioheat transfer equation, which represents a simplified model of heat transfer in the human body (ignoring strong blood vessel heat transport). Both PDEs need to be computed fast and to medical reliability (!) on a workstation within a clinical environment. This requirement triggered a series of new algorithmic developments to be reported here, among which is an adaptive multilevel FEM for Maxwell's equations, which dominates the numerical simulation time. In total, however, the main bulk of computation time (see Table 3 in Section 4 below) still goes into segmentation -- a necessary preprocessing step in the construction a 3D virtual patient from the input of a stack of 2D computed tomograms (left out here).}, language = {en} } @misc{LangErdmannSeebass, author = {Lang, Jens and Erdmann, Bodo and Seebass, Martin}, title = {Impact of Nonlinear Heat Transfer on Temperature Control in Regional Hyperthermia}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-3426}, number = {SC-97-73}, abstract = {We describe an optimization process specially designed for regional hyperthermia of deep seated tumors in order to achieve desired steady--state temperature distributions. A nonlinear three--dimensional heat transfer model based on temperature--dependent blood perfusion is applied to predict the temperature. Using linearly implicit methods in time and adaptive multilevel finite elements in space, we are able to integrate efficiently the instationary nonlinear heat equation with high accuracy. Optimal heating is obtained by minimizing an integral object function which measures the distance between desired and model predicted temperatures. A sequence of minima is calculated from successively improved constant--rate perfusion models employing a damped Newton method in an inner iteration. We compare temperature distributions for two individual patients calculated on coarse and fine spatial grids and present numerical results of optimizations for a Sigma 60 Applicator of the BSD 2000 Hyperthermia System.}, language = {en} } @misc{StallingSeebassZachow, author = {Stalling, Detlev and Seebass, Martin and Zachow, Stefan}, title = {Mehrschichtige Oberfl{\"a}chenmodelle zur computergest{\"u}tzten Planung in der Chirurgie}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-5661}, number = {TR-98-05}, abstract = {Polygonale Sch{\"a}delmodelle bilden ein wichtiges Hilfsmittel f{\"u}r computergest{\"u}tzte Planungen im Bereich der plastischen Chirurgie. Wir beschreiben, wie derartige Modelle automatisch aus hochaufgel{\"o}sten CT-Datens{\"a}tzen erzeugt werden k{\"o}nnen. Durch einen lokal steuerbaren Simplifizierungsalgorithmus werden die Modelle so weit vereinfacht, daß auch auf kleineren Graphikcomputern interaktives Arbeiten m{\"o}glich wird. Die Verwendung eines speziellen Transparenzmodells erm{\"o}glicht den ungehinderten Blick auf die bei der Planung relevanten Knochenstrukturen und l{\"a}ßt den Benutzer zugleich die Kopfumrisse des Patienten erkennen.}, language = {de} } @inproceedings{SeebassStallingHegeetal.1998, author = {Seebaß, Martin and Stalling, Detlev and Hege, Hans-Christian and Wust, Peter and Felix, Roland and Deuflhard, Peter}, title = {New Features of HyperPlan, a Hyperthermia Planning System}, series = {Proc. Hyperthermia in Clincal Oncology}, booktitle = {Proc. Hyperthermia in Clincal Oncology}, address = {Venice}, pages = {16}, year = {1998}, language = {en} } @inproceedings{NadobnyWustFaehlingetal.1998, author = {Nadobny, Jacek and Wust, Peter and F{\"a}hling, Horst and Stalling, Detlev and Seebaß, Martin and Deuflhard, Peter and Felix, Roland}, title = {Numerical and Experimental Evaluation of E-Field and Absorbed Power in the Pelvic Region Using a Bone-Equivalent Phantom}, series = {Proc. PIERS Progress in Electromagnetic Research Symposium}, booktitle = {Proc. PIERS Progress in Electromagnetic Research Symposium}, address = {Nantes}, pages = {264}, year = {1998}, language = {en} } @inproceedings{ErdmannLangSeebass1998, author = {Erdmann, Bodo and Lang, Jens and Seebass, Martin}, title = {Optimization of Temperature Distributions for Regional Hyperthermia based on a Nonlinear Heat Transfer Model}, series = {Biotransport}, volume = {858}, booktitle = {Biotransport}, editor = {Diller, K.}, pages = {36 -- 46}, year = {1998}, language = {en} }