@article{SponagelAkbay1984, author = {Sponagel, Stefan and Akbay, U.}, title = {{\"U}ber den Relaxationseinfluß auf die Stabilit{\"a}t der ebenen Couette-Str{\"o}mung. Akbay, U. ; Sponagel, S.}, series = {Rheologica Acta. 23 (1984), H. 2}, journal = {Rheologica Acta. 23 (1984), H. 2}, isbn = {0035-4511}, pages = {177 -- 184}, year = {1984}, language = {de} } @book{GrafGrossSponagel1988, author = {Graf, G{\"u}nter and Groß, Heinz and Sponagel, Stefan}, title = {Verfahren zur Herstellung eines Dichtringes : Europ{\"a}ische Patentschrift EP0250642B1 ; Ver{\"o}ffentlichungstag der Patentschrift: 11.02.1988}, publisher = {Europ{\"a}isches Patentamt}, address = {[M{\"u}nchen u.a.]}, pages = {5 S. : Ill.}, year = {1988}, language = {de} } @misc{SponagelWachowitz1992, author = {Sponagel, Stefan and Wachowitz, Waldemar}, title = {Shaft seal : United States Patent 5,143,385 ; date of patent: Sep. 1, 1992 / assignee: Firma Carl Freudenberg}, publisher = {[United States Patent and Trademark Office]}, address = {[Alexandria, VA]}, pages = {5 S. : Ill.}, year = {1992}, language = {en} } @misc{SponagelGrafGross1989, author = {Sponagel, Stefan and Graf, G{\"u}nter and Groß, Heinz}, title = {Method for manufacturing a sealing ring : United States Patent 4,861,536 ; date of patent: Aug. 12, 1989 / assignee: Firma Carl Freudenberg. Inventors: Gunter Graf ; Heinz Gross ; Stefan Sponagel}, publisher = {[United States Patent and Trademark Office]}, address = {[Alexandria, VA]}, pages = {5 S. : Ill.}, year = {1989}, language = {en} } @misc{SponagelGrafGross1989, author = {Sponagel, Stefan and Graf, G{\"u}nter and Groß, Heinz}, title = {Method for the manufacture of a sealing ring with a sealing lip having hydrodynamically acting return elements : United States Patent 4,850,097 ; date of patent: Jul. 25, 1989 / assignee: Firma Carl Freudenberg. Inventors: Gunter Graf ; Heinz Gross ; Stefan Sponagel}, publisher = {[United States Patent and Trademark Office]}, address = {[Alexandria, VA]}, pages = {4 S. : Ill.}, year = {1989}, language = {en} } @article{Sponagel1999, author = {Sponagel, Stefan}, title = {Der Mensch als L{\"a}ufer}, series = {Orthop{\"a}die und Sport : [Bericht zum Stolberger Orthop{\"a}dietag, 13. Juni 1998]}, journal = {Orthop{\"a}die und Sport : [Bericht zum Stolberger Orthop{\"a}dietag, 13. Juni 1998]}, publisher = {Meyer \& Meyer}, address = {Aachen}, isbn = {978-3-89124-540-8}, pages = {15 -- 21}, year = {1999}, language = {de} } @misc{SponagelMasbergHartmann1999, author = {Sponagel, Stefan and Masberg, Mariane and Hartmann, Jochen}, title = {Kraftfahrzeugk{\"u}hlwasserpumpe : Offenlegungsschrift DE19803739A1 ; Ver{\"o}ffentlichungstag im Patentblatt: 12.08.1999}, publisher = {Deutsches Patent- und Markenamt}, address = {M{\"u}nchen}, pages = {6 S. : Ill.}, year = {1999}, language = {de} } @misc{SponagelWachowitz1990, author = {Sponagel, Stefan and Wachowitz, Waldemar}, title = {Wellendichtung : Offenlegungsschrift DE3830706A1 ; Ver{\"o}ffentlichungstag im Patentblatt: 22.03.1990 / Anmelder: Fa. Carl Freudenberg}, publisher = {Deutsches Patent- und Markenamt}, address = {M{\"u}nchen}, pages = {4 S. : Ill.}, year = {1990}, language = {de} } @misc{GrafGrossSponagel1987, author = {Graf, G{\"u}nter and Groß, Heinz and Sponagel, Stefan}, title = {Verfahren zur Herstellung eines Dichtringes mit einer Dichtlippe : Patentschrift DE3621241C1 ; Ver{\"o}ffentlichungstag der Patenterteilung : 25.06.1987}, publisher = {Deutsches Patent- und Markenamt}, address = {M{\"u}nchen}, pages = {5 S. : Ill.}, year = {1987}, language = {de} } @misc{SponagelGrafGross1987, author = {Sponagel, Stefan and Graf, G{\"u}nter and Groß, Heinz}, title = {Verfahren zur Herstellung eines Dichtringes : Patentschrift DE3621242C1 ; Ver{\"o}ffentlichungstag der Patenterteilung : 25.06.1987 / Anmelder: Fa. Carl Freudenberg. Erfinder: G{\"u}nter Graf ; Heinz Groß ; Stefan Sponagel}, publisher = {Deutsches Patent- und Markenamt}, address = {M{\"u}nchen}, pages = {5 S. : Ill.}, year = {1987}, language = {de} } @book{SponagelWachowitz1993, author = {Sponagel, Stefan and Wachowitz, Waldemar}, title = {Wellendichtung : Europ{\"a}ische Patentschrift DE3621242C1 ; Ver{\"o}ffentlichungstag der Patentschrift : 06.06.1993 / Anmelder: Fa. Carl Freudenberg}, publisher = {Europ{\"a}isches Patentamt}, address = {[M{\"u}nchen u.a.]}, pages = {5 S. : Ill.}, year = {1993}, language = {de} } @article{SponagelUnger1998, author = {Sponagel, Stefan and Unger, J.}, title = {Organisation und Strukturierung technischer Messungen}, series = {Werkstattstechnik. 88 (1998), H. 5}, journal = {Werkstattstechnik. 88 (1998), H. 5}, isbn = {1436-5006}, pages = {223 -- 226}, year = {1998}, language = {de} } @article{BaroudWuBohneretal.2003, author = {Baroud, Gamal and Wu, J.Z. and Bohner, M and Sponagel, Stefan and Steffen, T.}, title = {How to determine the permeability for cement infiltration into osteoporotic cancellous bone}, series = {Medical Engineering \& Physics. 25 (2003), H. 4}, journal = {Medical Engineering \& Physics. 25 (2003), H. 4}, issn = {1350-4533}, pages = {283 -- 288}, year = {2003}, abstract = {Cement augmentation is an emerging surgical procedure in which bone cement is used to infiltrate and reinforce osteoporotic vertebrae. Although this infiltration procedure has been widely applied, it is performed empirically and little is known about the flow characteristics of cement during the injection process. We present a theoretical and experimental approach to investigate the intertrabecular bone permeability during the infiltration procedure. The cement permeability was considered to be dependent on time, bone porosity, and cement viscosity in our analysis. In order to determine the time-dependent permeability, ten cancellous bone cores were harvested from osteoporotic vertebrae, infiltrated with acrylic cement at a constant flow rate, and the pressure drop across the cores during the infiltration was measured. The viscosity dependence of the permeability was determined based on published experimental data. The theoretical model for the permeability as a function of bone porosity and time was then fit to the testing data. Our findings suggest that the intertrabecular bone permeability depends strongly on time. For instance, the initial permeability (60.89 mm4/N.s) reduced to approximately 63\% of its original value within 18 seconds. This study is the first to analyze cement flow through osteoporotic bone. The theoretical and experimental models provided in this paper are generic. Thus, they can be used to systematically study and optimize the infiltration process for clinical practice.}, subject = {Osteoporose}, language = {en} } @article{SponagelBaroudFalketal.2004, author = {Sponagel, Stefan and Baroud, Gamal and Falk, R. and Crookshank, M.}, title = {Experimental and theoretical investigation of directional permeability of human vertebral cancellous bone for cement infiltration. G. Baroud, R. Falk, M. Crookshank, S. Sponagel, T. Steffen}, series = {Journal of Biomechanics. 37 (2004), H. 2}, journal = {Journal of Biomechanics. 37 (2004), H. 2}, isbn = {0021-9290}, pages = {189 -- 196}, year = {2004}, language = {en} } @article{SponagelBaroudFalketal.2004, author = {Sponagel, Stefan and Baroud, Gamal and Falk, R. and Crookshank, M.}, title = {Corrigendum to "Experimental and theoretical investigation of directional permeability of human vertebral cancellous bone for cement infiltration". Baroud, G.; Falk, R.; Crookshank, M.; Sponagel, S.; Steffen, T.}, series = {Journal of Biomechanics. 37 (2004), H. 2}, journal = {Journal of Biomechanics. 37 (2004), H. 2}, isbn = {0021-9290}, pages = {1802}, year = {2004}, language = {en} } @article{SponagelBaroudSteffenetal.2002, author = {Sponagel, Stefan and Baroud, Gamal and Steffen, T. and Wu, J.}, title = {Parameter identification for cement infiltration of osteoporotic bone}, series = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...}, journal = {Poromechanics II : Proceedings of the Second Biot Conference on Poromechanics Grenoble, France 26 - 28 August 2002 / ed. by J.-L. Auriault ...}, publisher = {Balkema}, address = {Lisse [u.a.]}, isbn = {90-5809-394-8}, pages = {55 -- 58}, year = {2002}, language = {en} } @article{BehbahaniBehrHormesetal.2009, author = {Behbahani, Mehdi and Behr, M. and Hormes, M. and Steinseifer, U. and Arora, D. and Coronado, O. and Pasquali, M.}, title = {A Review of Computational Fluid Dynamics Analysis of Blood Pumps}, series = {European Journal of Applied Mathematics. 20 (2009), H. 4}, journal = {European Journal of Applied Mathematics. 20 (2009), H. 4}, publisher = {Cambridge Univ. Press}, address = {Cambridge}, pages = {363 -- 397}, year = {2009}, language = {en} } @article{BehbahaniFinocchiaroHeinkeetal.2009, author = {Behbahani, Mehdi and Finocchiaro, Thomas and Heinke, Stefanie and Leßmann, Marc}, title = {Methods of design, simulation, and control for the development of new VAD/TAH concepts = Methoden zur Konstruktion, Simulation und Regelung f{\"u}r die Entwicklung von neuen VAD/TAH-Konzepten / Finocchiaro, Thomas ; Heinke, Stefanie ; Behbahani, Mehdi ; Leßma}, series = {Biomedizinische Technik / Biomedical Engineering. 54 (2009), H. 5}, journal = {Biomedizinische Technik / Biomedical Engineering. 54 (2009), H. 5}, isbn = {0013-5585}, pages = {269 -- 281}, year = {2009}, language = {en} } @article{BehbahaniSpillnerKoppetal.2009, author = {Behbahani, Mehdi and Spillner, Jan and Kopp, R{\"u}diger and Finocchiaro, Thomas}, title = {Assistierte Zirkulation : ein {\"U}berblick aus klinischer Sicht = Assisted circulation: an overview from a clinical perspective / Spillner, Jan ; Kopp, R{\"u}diger ; Finocchiaro, Thomas ; Behbahani, Mehdi ; Rossaint, Rolf ; Steinseifer, Ulrich ; Behr, Marek ; Au}, series = {Biomedizinische Technik / Biomedical Engineering. 54 (2009), H. 5}, journal = {Biomedizinische Technik / Biomedical Engineering. 54 (2009), H. 5}, publisher = {De Gruyter}, address = {Berlin}, isbn = {0013-5585}, pages = {255 -- 267}, year = {2009}, language = {de} } @article{BehbahaniBehrNicolaietal.2008, author = {Behbahani, Mehdi and Behr, Marek and Nicolai, Mike and Probst, Markus}, title = {Towards Shape Optimization for Ventricular Assist Devices Using Parallel Stabilized FEM}, series = {NIC Symposium 2008 : symposium, 20 - 21 February 2008, Forschungszentrum J{\"u}lich ; proceedings / organized by John von Neumann Institute for Computing. Ed. by Gernot M{\"u}nster; Dietrich Wolf; Manfred Kremer (ed.)}, journal = {NIC Symposium 2008 : symposium, 20 - 21 February 2008, Forschungszentrum J{\"u}lich ; proceedings / organized by John von Neumann Institute for Computing. Ed. by Gernot M{\"u}nster; Dietrich Wolf; Manfred Kremer (ed.)}, publisher = {Forschungszentrum}, address = {J{\"u}lich}, isbn = {978-3-9810843-5-1}, pages = {325 -- 332}, year = {2008}, language = {en} }