@inproceedings{MarinovaKerroumiLintermannetal.2016, author = {Marinova, V. and Kerroumi, I. and Lintermann, A. and G{\"o}bbert, J.H. and Moulinec, C. and Rible, S. and Fournier, Y. and Behbahani, Mehdi}, title = {Numerical Analysis of the FDA Centrifugal Blood Pump}, series = {NIC Symposium 2016}, booktitle = {NIC Symposium 2016}, isbn = {978-3-95806-109-5}, pages = {355 -- 364}, year = {2016}, language = {de} } @article{FrotscherMuanghongDursunetal.2016, author = {Frotscher, Ralf and Muanghong, Danita and Dursun, G{\"o}zde and Goßmann, Matthias and Temiz Artmann, Ayseg{\"u}l and Staat, Manfred}, title = {Sample-specific adaption of an improved electro-mechanical model of in vitro cardiac tissue}, series = {Journal of Biomechanics}, volume = {49}, journal = {Journal of Biomechanics}, number = {12}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0021-9290 (Print)}, doi = {10.1016/j.jbiomech.2016.01.039}, pages = {2428 -- 2435}, year = {2016}, abstract = {We present an electromechanically coupled computational model for the investigation of a thin cardiac tissue construct consisting of human-induced pluripotent stem cell-derived atrial, ventricular and sinoatrial cardiomyocytes. The mechanical and electrophysiological parts of the finite element model, as well as their coupling are explained in detail. The model is implemented in the open source finite element code Code_Aster and is employed for the simulation of a thin circular membrane deflected by a monolayer of autonomously beating, circular, thin cardiac tissue. Two cardio-active drugs, S-Bay K8644 and veratridine, are applied in experiments and simulations and are investigated with respect to their chronotropic effects on the tissue. These results demonstrate the potential of coupled micro- and macroscopic electromechanical models of cardiac tissue to be adapted to experimental results at the cellular level. Further model improvements are discussed taking into account experimentally measurable quantities that can easily be extracted from the obtained experimental results. The goal is to estimate the potential to adapt the presented model to sample specific cell cultures.}, language = {en} } @inproceedings{JungStaatMueller2016, author = {Jung, Alexander and Staat, Manfred and M{\"u}ller, Wolfram}, title = {Effect of wind on flight style optimisation in ski jumping}, series = {15th International Symposium on Computer Simulation in Biomechanics ; July 9th-11th 2015, Edinburgh, UK}, booktitle = {15th International Symposium on Computer Simulation in Biomechanics ; July 9th-11th 2015, Edinburgh, UK}, publisher = {The University of Edinburgh ; Loughborough University}, address = {Edinburgh}, pages = {53 -- 54}, year = {2016}, language = {en} } @techreport{BhattaraiFrotscherDurongetal.2016, author = {Bhattarai, Aroj and Frotscher, Ralf and Durong, Minh Tu{\´a}n and Staat, Manfred}, title = {Schlussbericht zu BINGO. Optimierung des Systems Netzimplantat-Beckenboden zur therapeutischen Gewebeverst{\"a}rkung nach der Integraltheorie.}, address = {Aachen}, pages = {34}, year = {2016}, language = {de} } @article{GossmannFrotscherLinderetal.2016, author = {Goßmann, Matthias and Frotscher, Ralf and Linder, Peter and Bayer, Robin and Epple, U. and Staat, Manfred and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard}, title = {Mechano-pharmacological characterization of cardiomyocytes derived from human induced pluripotent stem cells}, series = {Cellular physiology and biochemistry}, volume = {38}, journal = {Cellular physiology and biochemistry}, number = {3}, publisher = {Karger}, address = {Basel}, issn = {1421-9778 (Online)}, doi = {10.1159/000443124}, pages = {1182 -- 1198}, year = {2016}, abstract = {Background/Aims: Common systems for the quantification of cellular contraction rely on animal-based models, complex experimental setups or indirect approaches. The herein presented CellDrum technology for testing mechanical tension of cellular monolayers and thin tissue constructs has the potential to scale-up mechanical testing towards medium-throughput analyses. Using hiPS-Cardiac Myocytes (hiPS-CMs) it represents a new perspective of drug testing and brings us closer to personalized drug medication. Methods: In the present study, monolayers of self-beating hiPS-CMs were grown on ultra-thin circular silicone membranes and deflect under the weight of the culture medium. Rhythmic contractions of the hiPS-CMs induced variations of the membrane deflection. The recorded contraction-relaxation-cycles were analyzed with respect to their amplitudes, durations, time integrals and frequencies. Besides unstimulated force and tensile stress, we investigated the effects of agonists and antagonists acting on Ca²⁺ channels (S-Bay K8644/verapamil) and Na⁺ channels (veratridine/lidocaine). Results: The measured data and simulations for pharmacologically unstimulated contraction resembled findings in native human heart tissue, while the pharmacological dose-response curves were highly accurate and consistent with reference data. Conclusion: We conclude that the combination of the CellDrum with hiPS-CMs offers a fast, facile and precise system for pharmacological, toxicological studies and offers new preclinical basic research potential.}, language = {en} } @article{AlbannaConzenWeissetal.2016, author = {Albanna, Walid and Conzen, Catharina and Weiss, Miriam and Clusmann, Hans and Fuest, Matthias and Mueller, Marguerite and Brockmann, Marc Alexander and Vilser, Walthard and Schmidt-Trucks{\"a}ss, Arno and Hoellig, Anke and Seiz, Marcel and Thom{\´e}, Claudius and Kotliar, Konstantin and Schubert, Gerrit Alexander}, title = {Retinal Vessel Analysis (RVA) in the context of subarachnoid hemorrhage: A proof of concept study}, series = {PLoS ONE}, volume = {11}, journal = {PLoS ONE}, number = {7}, publisher = {PLOS}, address = {San Francisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0158781}, pages = {13 Seiten}, year = {2016}, abstract = {Background Timely detection of impending delayed cerebral ischemia after subarachnoid hemorrhage (SAH) is essential to improve outcome, but poses a diagnostic challenge. Retinal vessels as an embryological part of the intracranial vasculature are easily accessible for analysis and may hold the key to a new and non-invasive monitoring technique. This investigation aims to determine the feasibility of standardized retinal vessel analysis (RVA) in the context of SAH. Methods In a prospective pilot study, we performed RVA in six patients awake and cooperative with SAH in the acute phase (day 2-14) and eight patients at the time of follow-up (mean 4.6±1.7months after SAH), and included 33 age-matched healthy controls. Data was acquired using a manoeuvrable Dynamic Vessel Analyzer (Imedos Systems UG, Jena) for examination of retinal vessel dimension and neurovascular coupling. Results Image quality was satisfactory in the majority of cases (93.3\%). In the acute phase after SAH, retinal arteries were significantly dilated when compared to the control group (124.2±4.3MU vs 110.9±11.4MU, p<0.01), a difference that persisted to a lesser extent in the later stage of the disease (122.7±17.2MU, p<0.05). Testing for neurovascular coupling showed a trend towards impaired primary vasodilation and secondary vasoconstriction (p = 0.08, p = 0.09 resp.) initially and partial recovery at the time of follow-up, indicating a relative improvement in a time-dependent fashion. Conclusion RVA is technically feasible in patients with SAH and can detect fluctuations in vessel diameter and autoregulation even in less severely affected patients. Preliminary data suggests potential for RVA as a new and non-invasive tool for advanced SAH monitoring, but clinical relevance and prognostic value will have to be determined in a larger cohort.}, language = {en} } @article{PeloniDachwaldCeriotti2017, author = {Peloni, Alessandro and Dachwald, Bernd and Ceriotti, Matteo}, title = {Multiple near-earth asteroid rendezvous mission: Solar-sailing options}, series = {Advances in Space Research}, journal = {Advances in Space Research}, number = {In Press, Corrected Proof}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0273-1177}, doi = {10.1016/j.asr.2017.10.017}, year = {2017}, language = {en} } @inproceedings{GrundmannBieleDachwaldetal.2017, author = {Grundmann, Jan Thimo and Biele, Jens and Dachwald, Bernd and Grimm, Christian D. and Lange, Caroline and Ulamec, Stephan and Ziach, Christian and Spr{\"o}witz, Tom and Ruffer, Michael and Seefeldt, Patric and Spietz, Peter and Toth, Norbert and Mimasu, Yuya and Rittweger, Andreas and Bibring, Jean-Pierre and Braukhane, Andy and Boden, Ralf Christian and Dumont, Etienne and Jahnke, Stephan Siegfried and Jetzschmann, Michael and Kr{\"u}ger, Hans and Lange, Michael and Gomez, Antonio Martelo and Massonett, Didier and Okada, Tatsuaki and Sagliano, Marco and Sasaki, Kaname and Schr{\"o}der, Silvio and Sippel, Martin and Skoczylas, Thomas and Wejmo, Elisabet}, title = {Small landers and separable sub-spacecraft for near-term solar sails}, series = {The Fourth International Symposium on Solar Sailing 2017}, booktitle = {The Fourth International Symposium on Solar Sailing 2017}, pages = {1 -- 10}, year = {2017}, abstract = {Following the successful PHILAE landing with ESA's ROSETTA probe and the launch of the MINERVA rovers and the Mobile Asteroid Surface Scout, MASCOT, aboard the JAXA space probe, HAYABUSA2, to asteroid (162173) Ryugu, small landers have found increasing interest. Integrated at the instrument level in their mothership they support small solar system body studies. With efficient capabilities, resource-friendly design and inherent robustness they are an attractive exploration mission element. We discuss advantages and constraints of small sub-spacecraft, focusing on emerging areas of activity such as asteroid diversity studies, planetary defence, and asteroid mining, on the background of our projects PHILAE, MASCOT, MASCOT2, the JAXA-DLR Solar Power Sail Lander Design Study, and others. The GOSSAMER-1 solar sail deployment concept also involves independent separable sub-spacecraft operating synchronized to deploy the sail. Small spacecraft require big changes in the way we do things and occasionally a little more effort than would be anticipated based on a traditional large spacecraft approach. In a Constraints-Driven Engineering environment we apply Concurrent Design and Engineering (CD/CE), Concurrent Assembly, Integration and Verification (CAIV) and Model-Based Systems Engineering (MBSE). Near-term solar sails will likely be small spacecraft which we expect to harmonize well with nano-scale separable instrument payload packages.}, language = {en} } @inproceedings{GrundmannMessBieleetal.2017, author = {Grundmann, Jan Thimo and Meß, Jan-Gerd and Biele, Jens and Seefeldt, Patric and Dachwald, Bernd and Spietz, Peter and Grimm, Christian D. and Spr{\"o}witz, Tom and Lange, Caroline and Ulamec, Stephan}, title = {Small spacecraft in small solar system body applications}, series = {IEEE Aerospace Conference 2017, Big Sky, Montana, USA}, booktitle = {IEEE Aerospace Conference 2017, Big Sky, Montana, USA}, organization = {IEEE Aerospace Conference}, isbn = {978-1-5090-1613-6}, doi = {10.1109/AERO.2017.7943626}, pages = {1 -- 20}, year = {2017}, language = {en} } @inproceedings{PeloniDachwaldCeriotti2017, author = {Peloni, Alessandro and Dachwald, Bernd and Ceriotti, Matteo}, title = {Multiple NEA rendezvous mission: Solar sailing options}, series = {Fourth International Symposium on Solar Sailing}, booktitle = {Fourth International Symposium on Solar Sailing}, pages = {1 -- 11}, year = {2017}, abstract = {The scientific interest in near-Earth asteroids (NEAs) and the classification of some of those as potentially hazardous asteroid for the Earth stipulated the interest in NEA exploration. Close-up observations of these objects will increase drastically our knowledge about the overall NEA population. For this reason, a multiple NEA rendezvous mission through solar sailing is investigated, taking advantage of the propellantless nature of this groundbreaking propulsion technology. Considering a spacecraft based on the DLR/ESA Gossamer technology, this work focuses on the search of possible sequences of NEA encounters. The effectiveness of this approach is demonstrated through a number of fully-optimized trajectories. The results show that it is possible to visit five NEAs within 10 years with near-term solar-sail technology. Moreover, a study on a reduced NEA database demonstrates the reliability of the approach used, showing that 58\% of the sequences found with an approximated trajectory model can be converted into real solar-sail trajectories. Lastly, this second study shows the effectiveness of the proposed automatic optimization algorithm, which is able to find solutions for a large number of mission scenarios without any input required from the user.}, language = {en} }