TY - JOUR A1 - Maiwald, Volker A1 - Dachwald, Bernd T1 - Mission Design for a Multiple-Rendezvous Mission to Jupiter's Trojans Y1 - 2010 N1 - COSPAR 2010 ; 38th COSPAR Scientific Assembly. Held 18-25 July 2010 in Bremen, Germany [Abstract] SP - 3 ER - TY - JOUR A1 - Dachwald, Bernd A1 - Tsinas, L. T1 - A combined neural and genetic learning algorithm / Tsinas, L. ; Dachwald, B. JF - Proceedings of the First IEEE Conference on Evolutionary Computation, 1994. IEEE World Congress on Computational Intelligence. Y1 - 1994 SN - 0-7803-1899-4 SP - 770 EP - 774 CY - Orlando, Fl ER - TY - JOUR A1 - Baader, Fabian A1 - Boxberg, Marc S. A1 - Chen, Qian A1 - Förstner, Roger A1 - Kowalski, Julia A1 - Dachwald, Bernd T1 - Field-test performance of an ice-melting probe in a terrestrial analogue environment JF - Icarus N2 - Melting probes are a proven tool for the exploration of thick ice layers and clean sampling of subglacial water on Earth. Their compact size and ease of operation also make them a key technology for the future exploration of icy moons in our Solar System, most prominently Europa and Enceladus. For both mission planning and hardware engineering, metrics such as efficiency and expected performance in terms of achievable speed, power requirements, and necessary heating power have to be known. Theoretical studies aim at describing thermal losses on the one hand, while laboratory experiments and field tests allow an empirical investigation of the true performance on the other hand. To investigate the practical value of a performance model for the operational performance in extraterrestrial environments, we first contrast measured data from terrestrial field tests on temperate and polythermal glaciers with results from basic heat loss models and a melt trajectory model. For this purpose, we propose conventions for the determination of two different efficiencies that can be applied to both measured data and models. One definition of efficiency is related to the melting head only, while the other definition considers the melting probe as a whole. We also present methods to combine several sources of heat loss for probes with a circular cross-section, and to translate the geometry of probes with a non-circular cross-section to analyse them in the same way. The models were selected in a way that minimizes the need to make assumptions about unknown parameters of the probe or the ice environment. The results indicate that currently used models do not yet reliably reproduce the performance of a probe under realistic conditions. Melting velocities and efficiencies are constantly overestimated by 15 to 50 % in the models, but qualitatively agree with the field test data. Hence, losses are observed, that are not yet covered and quantified by the available loss models. We find that the deviation increases with decreasing ice temperature. We suspect that this mismatch is mainly due to the too restrictive idealization of the probe model and the fact that the probe was not operated in an efficiency-optimized manner during the field tests. With respect to space mission engineering, we find that performance and efficiency models must be used with caution in unknown ice environments, as various ice parameters have a significant effect on the melting process. Some of these are difficult to estimate from afar. Y1 - 2023 U6 - https://doi.org/10.1016/j.icarus.2023.115852 N1 - Forschungsdaten hierzu: "Performance data of an ice-melting probe from field tests in two different ice environments" (https://opus.bibliothek.fh-aachen.de/opus4/frontdoor/index/index/docId/10890) IS - 409 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Artmann, Gerhard A1 - Kelemen, Christina A1 - Porst, Dariusz A1 - Büldt, G. [u.a.] T1 - Temperature transitions of protein properties in human red blood cells. Artmann, Gerhard Michael, Kelemen, Christina; Porst, D.; Büldt, G.; Chien, S. JF - Biophysical Journal. 75 (1998), H. 6 Y1 - 1998 SN - 1542-0086 N1 - http://www.pubmedcentral.nih.gov/picrender.fcgi?artid=1299989&blobtype=pdf SP - 3179 EP - 3183 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Shi, Young de A1 - Agosti, R. A1 - Longhini, E. T1 - A modified casson equation to characterize blood rheology for hypertension. Shi, Young de; Artmann, Gerhard Michael; Agosti, R.; Longhini, E. JF - Clinical Hemorheology Microcirculation. 19 (1998), H. 2 Y1 - 1998 SN - 1386-0291 SP - 115 EP - 127 ER - TY - JOUR A1 - Li, Anlan A1 - Shi, Young de A1 - Landsmann, B. A1 - Schankowski-Bouvier, P. A1 - Dikta, Gerhard A1 - Bauer, U. A1 - Artmann, Gerhard T1 - Hemorheology and walking distance of Peripheral Arterial Occlusive Disease patients during treatment with Ginkgo-biloba extract JF - Acta Pharmacologica Sinica = ZHONGUO YAOLI XUEBAO. 19 (1998), H. 5 Y1 - 1998 SN - 1745-7254 N1 - ISSN der parallelen Ausgabe 1671-4083; China-Zs.-Code: CN31-1347 abstract frei unter SP - 417 EP - 421 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Sung, K.-L. Paul A1 - Horn, Thomas A1 - Whittemore, Darren [u.a.] T1 - Micropipette aspiration of human erythrocytes induces echinocytes via membrane phospholipid translocation. Artmann, Gerhard Michael; Sung, K.-L. Paul; Horn, Thomas; Whittemore, Darren; Norwich, Gerald; Chien, Shu JF - Biophysical journal. 72 (1997), H. 3 Y1 - 1997 SN - 1542-0086 SP - 1434 EP - 1441 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, Jürgen A1 - Ates, M. T1 - A novel method to quantify mechanical tension in cell monolayers. Trzewik, Jürgen; Ates, M., Artmann, Gerhard Michael JF - Biomedizinische Technik. 47 (2002), H. Suppl. 1. Pt. 1 Y1 - 2002 SN - 0013-5585 N1 - Druckausgabe unter 63 Z 47 vorhanden SP - 379 EP - 381 ER - TY - JOUR A1 - Maggakis-Kelemen, Christina A1 - Biselli, Manfred A1 - Artmann, Gerhard T1 - Determination of the elastic shear modulus of cultured human red blood cells JF - Biomedizinische Technik. 47 (2002), H. Suppl. 1 Pt. 1 Y1 - 2002 SN - 0013-5585 N1 - Druckausgabe unter 63 Z 471 vorhanden SP - 106 EP - 109 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Zhou-Stache, J. A1 - Buettner, R. A1 - Mittermayer, C. [u.a.] T1 - Inhibition of TNF-alpha induced cell death in HUVEC and Jurkat cells by protocatechuic acid. Zhou-Stache, J.; Buettner, R.; Artmann, Gerhard Michael; Mittermayer, C.; Bosserhoff, A. K. JF - Medical and Biological Engineering and Computing. 40 (2002), H. 6 Y1 - 2002 SN - 0140-0118 SP - 698 EP - 703 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, Jürgen A1 - Mallipattu, S. K. A1 - Delano, F. A. [u.a.] T1 - Evidence for a second valve system in Lymphatics: Endothelial Microvalves. Trzewik, Jürgen; Mallipattu, S. K.; Artmann, Gerhard Michael; Delano, F. A.; Schmid-Schonbein, G. W JF - The FASEB Journal. 15 (2001) Y1 - 2001 SN - 1530-6860 SP - 1711 EP - 1717 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Bäumler, H. A1 - Voigt, A. A1 - Mitlöhner, R. [u.a.] T1 - Plastic behaviour of polyelectrolyte microcapsules derived from colloid templates. Bäumler, H., Artmann, Gerhard Michael; Voigt, A., Mitlöhner, R., Neu, B., Kiesewetter, H. JF - Journal of Microencapsulation. 17 (2000), H. 5 Y1 - 2000 SN - 1464-5246 SP - 651 EP - 655 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Gorbatenkova, E. A. A1 - Panasenko, O. M. T1 - Hypochlorous acid and human blood low density lipoproteins modified by hypochlorous acid increase erythrocyte adhesion to endothelial cells. Gorbatenkova, E. A.; Artmann, Gerhard Michael; Panasenko, O. M. JF - Membrane and cell biology. 13 (2000), H. 4 Y1 - 2000 SN - 1023-6597 SP - 537 EP - 546 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Kelemen, C. A1 - Chien, S. T1 - Temperature transition of human hemoglobin at body temperature: effects of calcium. Kelemen, C.; Chien, S.; Artmann, Gerhard Michael JF - Biophysical journal. 80 (2001), H. 6 Y1 - 2001 SN - 1542-0086 SP - 2622 EP - 2630 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Hueck, I. S. A1 - Hollweg, H. G. A1 - Schmid-Schönbein, G. W. T1 - Chlorpromazine modulates the Morphological Macro- and Microstructure of Endothelial Cells. Hueck, I. S.; Hollweg, H. G.; Schmid-Schönbein, G. W.; Artmann, Gerhard Michael JF - American Journal of Physiology. Cell Physiology. 278 (2000), H. 5 Y1 - 2000 SN - 1522-1563 N1 - Zählung: C873- C878 SP - 873 EP - 878 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Li, Anlan A1 - Seipelt, H. A1 - Müller, C. [u.a.] T1 - Effects of salicylic acid derivatives on red blood cell membranes. Li, Anlan; Seipelt, H.; Müller, C.;Shi, Yong de; Artmann, Gerhard Michael JF - Pharmacology and Toxicology. 85 (1999) Y1 - 1999 SN - 0902-9938 SP - 206 EP - 211 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Hovav, T. A1 - Goldfarb, A. A1 - Yedgar, S. [u.a.] T1 - Enhanced adherence of beta-thalassaemic erythrocytes to endothelial cells. Hovav, T., Goldfarb, A.; Artmann, Gerhard Michael, Yedgar, S.; Barstein, G. JF - British Journal of Haematology. 106 (1999), H. 1 Y1 - 1999 SN - 1365-2141 SP - 178 EP - 181 ER - TY - JOUR A1 - Artmann, Gerhard T1 - A microscopic photometric method for measuring erythrocyte deformability. Artmann, Gerhard Michael JF - Clinical Hemorheology. 6 (1986) Y1 - 1986 SN - 0271-5198 SP - 617 EP - 627 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Schmid-Schönbein, H. A1 - Grebe, R. A1 - Teitel, P. [u.a.] T1 - Restoration of Microsieve Filterability of Human Red Cells After Exposure to Hyperosmolarity and Lactazidosis: Effect of Vinpocetine. Schmid-Schönbein, H.; Grebe, R.; Teitel, P.; Artmann, Gerhard Michael, Eschweiler, H.; Schröder, Susanne JF - Drug Development Research. 14 (1988), H. 3-4 Y1 - 1988 SN - 1098-2299 N1 - Abstracts frei unter: SP - 205 EP - 211 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Schmid-Schönbein, H. A1 - Schröder, Susanne A1 - Grebe, R. [u.a.] T1 - Influence of Moxaverine-HCL on Membrane Curvature and Microsieve Filterability of Red Cells after Exposure to Hyperosmolarity and Lactacidosis. Schmid-Schönbein, H.; Schröder, Susanne; Grebe, R.; Artmann, Gerhard Michael, Eschweiler, H; Teitel, P. JF - Arzneimittelforschung. 38 (1988), H. 5 Y1 - 1988 SN - 0004-4172 SP - 710 EP - 716 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Zang, Werner T1 - Fully automatic measurement of rheologic parameters of red blood cells = Laborautomat zur Messung mechanischer Eigenschaften roter Blutzellen JF - Biomedizinische Technik = Biomedical engineering. 35 (1990), H. Suppl. 3 Y1 - 1990 SN - 0013-5585 SP - 94 EP - 96 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Li, Anlan A1 - Ziemer, J. A1 - Schneider, G. [u.a.] T1 - A photometric method to analyze induced erythrocyte shape changes. Artmann, Gerhard Michael; Li, Anlan; Ziemer, J.; Schneider, G.; Sahm, U.: ; Ziemer, J.; Schneider, G.; Sahm, U. JF - Biorheology. 33 (1996), H. 3 Y1 - 1996 SN - 0006-355x SP - 251 EP - 265 ER - TY - JOUR A1 - Artmann, Gerhard T1 - 2nd International Conference on Medical Biorheology (ICMB). Shanghai, China, September 13-15, 1995. Shi, Young de, Artmann, Gerhard Michael, Meiselman, Herbert J. JF - Biorheology. 33 (1996), H. 6 Y1 - 1996 SN - 0006-355x SP - 505 EP - 507 ER - TY - JOUR A1 - Artmann, Gerhard T1 - Microscopic photometric quantification of stiffness and relaxation time of red blood cells in a flow chamber. Artmann, Gerhard Michael JF - Biorheology. 32 (1995), H. 5 Y1 - 1995 SN - 0006-355x SP - 553 EP - 570 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Li, Anlan T1 - Dihydroergocryptine maintains erythrocyte fluidity in acidotic and hyperosmolar suspensions modelling hypoxic and ischemic microcirculation. Li, Anlan; Artmann, Gerhard Michael JF - Clinical Hemorheology. 15 (1994), H. 2 Y1 - 1994 SN - 0271-5198 SP - 133 EP - 146 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Schmid-Schönbein, H. T1 - The microscope-photometrical-monolayer-technique- a new principle for analyzing the distribution of rheological responses in pathological and experimentally modified red cell populations. Artmann, Gerhard Michael; Schmid-Schönbein, H. JF - Microcirculation, an update : proceedings of the Fourth World Congress for Microcirculation, Tokyo, Japan, July 26-30, 1987 Y1 - 1987 SN - 0444809511 N1 - World Congress for Microcirculation (4, 1987, Tokyo;); International congress series ; 755 SP - 475 EP - 477 PB - Excerpta Medica CY - Amsterdam [u.a.] ER - TY - JOUR A1 - Artmann, Gerhard A1 - Schikarsky, C. T1 - Ginkgo Biloba extract (EGb 761) protects red blood cells from oxidative damage. Artmann, Gerhard Michael; Schikarsky, C. JF - Clinical Hemorheology. 13 (1993), H. 4 Y1 - 1993 SN - 0271-5198 SP - 529 EP - 539 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Hueck, Isgard S. A1 - Rossiter, Katharine A1 - Schmid-Schönbein, Geert W. T1 - Fluid Shear Attenuates Endothelial Pseudopodia Formation into the Capillary Lumen / Hueck, Isgard S. ; Rossiter, Katharine ; Artman, Gerhard M. ; Schmid-Schönbein, Geert W. JF - Microcirculation. 15 (2008), H. 6 Y1 - 2008 SN - 1549-8719 SP - 531 EP - 542 ER - TY - JOUR A1 - Eijck, Lambert van A1 - Demmel, Franz A1 - Artmann, Gerhard A1 - Stadtler, Andreas Maximilian T1 - Macromolecular dynamics in red blood cells investigated using neutron spectroscopy JF - Journal of the Royal Society Interface Y1 - 2011 SN - 1742-5689 VL - 8 IS - 57 SP - 590 EP - 600 PB - The Royal Society CY - London ER - TY - JOUR A1 - Becker, C. A1 - Wallang, C. A1 - Artmann, Gerhard A1 - Jakse, G. T1 - Mechanotransduction-bioreactor for tissue engineering of a ureter prosthesis JF - International Journal of Artificial Organs, The Y1 - 2008 SN - 0391-3988 N1 - Abstracts from the XXXV Congress of the European Society for Artificial Organs: 'Towards Future Biomedical Technologies' - ORAL PRESENTATIONS VL - 31 IS - 7 SP - 583 EP - 583 ER - TY - JOUR A1 - Artmann, Gerhard T1 - Cellular engineering - a challenge for engineers? / Artmann, G. M. JF - Biomedizinische Technik = Biomedical Engineering. 45 (2000), H. s1 Y1 - 2000 SN - 1862-278X SP - 449 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Trzewik, J. A1 - Schmid-Schönbein, G. W. T1 - Investigation on lymphatic endothelial microvalves / Trzewik, J. ; Artmann, G. M. ; Schmid-Schönbein, G. W. JF - Biomedizinische Technik = Biomedical Engineering. 45 (2000), H. s1 Y1 - 2000 SN - 1862-278X SP - 521 EP - 522 ER - TY - JOUR A1 - Artmann, Gerhard A1 - Kelemen, C. A1 - Porst, Dariusz A1 - Büldt, G. T1 - Cellular engineering: Crash tests an menschlichen Erythrozyten geben Aufschluß über versteckte Materialeigenschaften zellulärer Proteine / Artmann, G. M. ; Kelemen, Ch. ; Porst, D. ; Büldt, G. ; Chien, Shu JF - Biomedizinische Technik / Biomedical Engineering. 43 (1998), H. s1 Y1 - 1998 SN - 1862-278 SP - 446 EP - 447 ER - TY - JOUR A1 - Maggakis-Kelemen, C. A1 - Bork, M. A1 - Kayser, Peter A1 - Biselli, Manfred A1 - Artmann, Gerhard T1 - Biological and mechanical quality of red blood cells cultured from human umbilical cord blood stem cells JF - Medical and biological engineering and computing. 41 (2003), H. 3 Y1 - 2003 SN - 0140-0118 SP - 350 EP - 356 ER - TY - JOUR A1 - Kaul, D. K. A1 - Koshkaryev, A. A1 - Artmann, Gerhard A1 - Barshtein, G. A1 - Yedgar, S. T1 - Additive effect of red blood cell rigidity and adherence to endothelial cells in inducing vascular resistance JF - American Journal of Physiology : Heart and Circulation Physiology . 295 (2008), H. 4 Y1 - 2008 SN - 1522-1539 VL - 295 IS - 4 SP - H1788 EP - H1793 ER - TY - JOUR A1 - Stadler, Alexander Maximilian A1 - Garvey, Christopher J. A1 - Embs, Jan Peter A1 - Koza, Michael Marek A1 - Unruh, Tobias A1 - Artmann, Gerhard A1 - Zaccai, Guiseppe T1 - Picosecond dynamics in haemoglobin from different species: A quasielastic neutron scattering study JF - Biochimica et biophysica acta (BBA): General Subjects Y1 - 2014 U6 - https://doi.org/10.1016/j.bbagen.2014.06.007 SN - 1872-8006 (E-Journal); 0304-4165 (Print) VL - 1840 IS - 10 SP - 2989 EP - 2999 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Artmann, Gerhard A1 - Grebe, R. A1 - Homrighausen, A. A1 - Wolff, H. A1 - Teitel, P. A1 - Schmid-Schönbein, H. T1 - Response of normal and diabetic erythrocytes to membrane deformation by chemical and mechanical forces. Artmann, Gerhard Michael; Grebe, R.; Homrighausen, A.; Wolff, H.; Teitel, P.; Schmid-Schönbein, H. JF - 12. Jahrestagung der Gesellschaft für Mikrozirkulation Y1 - 1988 SP - 196 EP - 200 PB - Karger [u.a.] CY - Basel [u.a.] ER - TY - JOUR A1 - Tran, Thanh Ngoc A1 - Kreißig, R. A1 - Vu, Duc Khoi A1 - Staat, Manfred T1 - Upper bound limit and shakedown analysis of shells using the exact Ilyushin yield surface JF - Computer & Structures. 86 (2008) Y1 - 2008 SN - 0045-7949 SP - 1683 EP - 1695 ER - TY - JOUR A1 - Jung, Alexander A1 - Müller, Wolfram A1 - Staat, Manfred T1 - Wind and fairness in ski jumping: A computer modelling analysis JF - Journal of Biomechanics N2 - Wind is closely associated with the discussion of fairness in ski jumping. To counter-act its influence on the jump length, the International Ski Federation (FIS) has introduced a wind compensation approach. We applied three differently accurate computer models of the flight phase with wind (M1, M2, and M3) to study the jump length effects of various wind scenarios. The previously used model M1 is accurate for wind blowing in direction of the flight path, but inaccuracies are to be expected for wind directions deviating from the tangent to the flight path. M2 considers the change of airflow direction, but it does not consider the associated change in the angle of attack of the skis which additionally modifies drag and lift area time functions. M3 predicts the length effect for all wind directions within the plane of the flight trajectory without any mathematical simplification. Prediction errors of M3 are determined only by the quality of the input data: wind velocity, drag and lift area functions, take-off velocity, and weight. For comparing the three models, drag and lift area functions of an optimized reference jump were used. Results obtained with M2, which is much easier to handle than M3, did not deviate noticeably when compared to predictions of the reference model M3. Therefore, we suggest to use M2 in future applications. A comparison of M2 predictions with the FIS wind compensation system showed substantial discrepancies, for instance: in the first flight phase, tailwind can increase jump length, and headwind can decrease it; this is opposite of what had been anticipated before and is not considered in the current wind compensation system in ski jumping. Y1 - 2018 U6 - https://doi.org/10.1016/j.jbiomech.2018.05.001 SN - 0021-9290 IS - 75 SP - 147 EP - 153 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jung, Alexander A1 - Staat, Manfred A1 - Müller, Wolfram T1 - Corrigendum to “Flight style optimization in ski jumping on normal, large, and ski flying hills” [J. Biomech 47 (2014) 716–722] JF - Journals of Biomechanics Y1 - 2018 U6 - https://doi.org/10.1016/j.jbiomech.2018.02.001 SN - 0021-9290 N1 - refers to Journal of Biomechanics Vol 47, Issue 3, Pages 716-722: https://doi.org/10.1016/j.jbiomech.2013.11.021 SP - 313 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Frotscher, Ralf A1 - Koch, Jan-Peter A1 - Staat, Manfred T1 - Computational investigation of drug action on human-induced stem cell derived cardiomyocytes JF - Journal of biomechanical engineering Y1 - 2015 U6 - https://doi.org/10.1115/1.4030173 SN - 1528-8951 (E-Journal); 0148-0731 (Print) VL - Vol. 137 IS - iss. 7 SP - 071002-1 EP - 071002-7 PB - ASME CY - New York ER - TY - JOUR A1 - Staat, Manfred T1 - Failure probabilities of the primary circuit pressure boundary of an HTR-Module for process heat generation under accident conditions for different failure modes JF - Nuclear Engineering and Design. 144 (1993), H. 1 Y1 - 1993 SN - 0029-5493 SP - 53 EP - 67 ER - TY - JOUR A1 - Staat, Manfred T1 - Plastic collapse analysis of longitudinally flawed pipes and vessels JF - Nuclear Engineering and Design. 234 (2004), H. 1-3 Y1 - 2004 SN - 0029-5493 SP - 25 EP - 43 ER - TY - JOUR A1 - Staat, Manfred A1 - Vu, Duc-Khoi T1 - An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress JF - Proceedings in Applied Mathematics and Mechanics (PAMM). 4 (2004), H. 1 Y1 - 2004 SN - 1617-7061 SP - 231 EP - 233 ER - TY - JOUR A1 - Staat, Manfred T1 - Local and global collapse pressure of longitudinally flawed pipes and cylindrical vessels JF - International Journal of Pressure Vessels and Piping. 82 (2005), H. 3 Y1 - 2005 SN - 0308-0161 SP - 217 EP - 225 ER - TY - JOUR A1 - Staat, Manfred A1 - Heitzer, M. T1 - Limit and Shakedown Analysis for Plastic Safety of Complex Structures JF - Transactions of the 14th International Conference on Structural Dynamics in Reactor Technology (SMiRT-14) / Livolant, M. [ed] Y1 - 1997 N1 - Vol. B, Paper B02/2 SP - 33 EP - 40 CY - Lyon ER - TY - JOUR A1 - Defosse, Jerome A1 - Kleinschmidt, Joris A1 - Schmutz, Axel A1 - Loop, Torsten A1 - Staat, Manfred A1 - Gatzweiler, Karl-Heinz A1 - Wappler, Frank A1 - Schieren, Mark T1 - Dental strain on maxillary incisors during tracheal intubation with double-lumen tubes and different laryngoscopy techniques - a blinded manikin study JF - Journal of Cardiothoracic and Vascular Anesthesia KW - anaesthetic complications KW - dental trauma KW - difficult airway KW - double-lumen tube intubation KW - videolaryngoscopy Y1 - 2022 U6 - https://doi.org/10.1053/j.jvca.2022.02.017 SN - 1053-0770 VL - 36 IS - 8, Part B SP - 3021 EP - 3027 PB - Elsevier CY - New York, NY ER - TY - JOUR A1 - Bhattarai, Aroj A1 - Jabbari, Medisa A1 - Anding, Ralf A1 - Staat, Manfred T1 - Surgical treatment of vaginal vault prolapse using different prosthetic mesh implants: a finite element analysis JF - tm - Technisches Messen N2 - Particularly multiparous elderly women may suffer from vaginal vault prolapse after hysterectomy due to weak support from lax apical ligaments. A decreased amount of estrogen and progesterone in older age is assumed to remodel the collagen thereby reducing tissue stiffness. Sacrocolpopexy is either performed as open or laparoscopic surgery using prosthetic mesh implants to substitute lax ligaments. Y-shaped mesh models (DynaMesh, Gynemesh, and Ultrapro) are implanted in a 3D female pelvic floor finite element model in the extraperitoneal space from the vaginal cuff to the first sacral (S1) bone below promontory. Numerical simulations are conducted during Valsalva maneuver with weakened tissues modeled by reduced tissue stiffness. Tissues are modeled as incompressible, isotropic hyperelastic materials whereas the meshes are modeled either as orthotropic linear elastic or as isotropic hyperlastic materials. The positions of the vaginal cuff and the bladder base are calculated from the pubococcygeal line for female pelvic floor at rest, for prolapse and after repair using the three meshes. Due to mesh mechanics and mesh pore deformation along the loaded direction, the DynaMesh with regular rectangular mesh pores is found to provide better mechanical support to the organs than the Gynemesh and the Ultrapro with irregular hexagonal mesh pores. Insbesondere ältere, mehrgebährende Frauen leiden häufiger an einem Scheidenvorfall nach einer Hysterektomie aufgrund der schwachen Unterstützung durch laxe apikale Bänder. Es wird angenommen, dass eine verringerte Menge an Östrogen und Progesteron im höheren Alter das Kollagen umformt, wodurch die Gewebesteifigkeit reduziert wird. Die Sakrokolpopexie ist eine offene oder laparoskopische Operation, die mit prothetischen Netzimplantaten durchgeführt wird, um laxe Bänder zu ersetzen. Y-förmige Netzmodelle (DynaMesh, Gynemesh und Ultrapro) werden in einem 3D-Modell des weiblichen Beckenbodens im extraperitonealen Raum vom Vaginalstumpf bis zum Promontorium implantiert. Numerische Simulationen werden während des Valsalva-Manövers mit geschwächtem Gewebe durchgeführt, das durch eine reduzierte Gewebesteifigkeit modelliert wird. Die Gewebe werden als inkompressible, isotrop hyperelastische Materialien modelliert, während die Netze entweder als orthotrope linear elastische oder als isotrope hyperlastische Materialien modelliert werden. Die Positionen des Vaginalstumpfs, der Blase und der Harnröhrenachse werden anhand der Pubococcygeallinie aus der Ruhelage, für den Prolaps und nach der Reparatur unter Verwendung der drei Netze berechnet. Aufgrund der Netzmechanik und der Netzporenverformung bietet das DynaMesh mit regelmäßigen rechteckigen Netzporen eine bessere mechanische Unterstützung und eine Neupositionierung des Scheidengewölbes, der Blase und der Urethraachse als Gynemesh und Ultrapro mit unregelmäßigen hexagonalen Netzporen. Y1 - 2018 U6 - https://doi.org/10.1515/teme-2017-0115 SN - 2196-7113 VL - 85 IS - 5 SP - 331 EP - 342 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Birgel, Stefan A1 - Leschinger, Tim A1 - Wegmann, Kilian A1 - Staat, Manfred T1 - Calculation of muscle forces and joint reaction loads in the shoulder area via an OpenSim based computer model JF - tm - Technisches Messen N2 - Using the OpenSim software and verified anatomical data, a computer model for the calculation of biomechanical parameters is developed and used to determine the effect of a reattachment of the Supraspinatus muscle with a medial displacement of the muscle attachment point, which may be necessary for a rupture of the supraspinatus tendon. The results include the influence of the operation on basic biomechanical parameters such as the lever arm, as well as the calculated the muscle activations for the supraspinatus and deltoid. In addition, the influence on joint stability is examined by an analysis of the joint reaction force. The study provides a detailed description of the used model, as well as medical findings to a reattachment of the supraspinatus. Mit der Software OpenSim und überprüften anatomischen Daten wird ein Computermodell zur Berechnung von biomechanischen Parametern entwickelt und genutzt, um den Effekt einer Refixierung des Supraspinatusmuskels mit einer medialen Verschiebung des Muskelansatzpunktes zu ermitteln, wie sie unter anderem nach einem Riss der Supraspinatussehne notwendig sein kann. Die Ergebnisse umfassen hierbei den Einfluss der Operation auf grundlegende biomechanische Parameter wie den Hebelarm sowie die berechneten Muskelaktivierungen für den Supraspinatus und Deltoideus. Zusätzlich wird der Einfluss auf die Gelenkstabilität betrachtet und durch eine Analyse der Gelenkreaktionskraft untersucht. Die Studie bietet eine detaillierte Beschreibung des genutzten Modells, sowie medizinische Erkenntnisse zu einer Refixierung des Supraspinatus. Y1 - 2018 U6 - https://doi.org/10.1515/teme-2017-0114 SN - 2196-7113 VL - 85 IS - 5 SP - 321 EP - 330 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Rausch, Valentin A1 - Harbrecht, Andreas A1 - Kahmann, Stephanie Lucina A1 - Fenten, Thomas A1 - Jovanovic, Nebojsa A1 - Hackl, Michael A1 - Müller, Lars P. A1 - Staat, Manfred A1 - Wegmann, Kilian T1 - Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws JF - The Journal of Hand Surgery N2 - Purpose The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. Methods A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. Results Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. Conclusions Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. Clinical relevance Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties. Y1 - 2020 U6 - https://doi.org/10.1016/j.jhsa.2020.04.010 SN - 0363-5023 VL - 45 IS - 10 SP - 987.e1 EP - 987.e8 PB - Elsevier CY - Amsterdam ER -