TY - JOUR A1 - Jansen, S. V. A1 - Behbahani, Mehdi A1 - Laumen, M. A1 - Kaufmann, T. A1 - Hormes, M. A1 - Behr, M. A1 - Schmitz-Rode, T. A1 - Steinseifer, U. T1 - Investigation of Steady Flow Through a Realistic Model of the Thoracic Human Aorta Using 3D Stereo PIV and CFD-Simulation Y1 - 2010 N1 - Posterpresentation ; American Society of Artificial Organs (ASAIO), Baltimore, USA, May 27-29, 2010 ER - TY - JOUR A1 - Jansen, Sebastian A1 - Behbahani, Mehdi A1 - Laumen, Marco A1 - Kaufmann, Tim A1 - Hormes, Marcus A1 - Schmitz-Rode, Thomas A1 - Behr, Marek A1 - Steinseifer, Ulrich T1 - 3D Stereo-PIV Validation for CFD-Simulation of Steady Flow through the Human Aorta using Rapid-Prototyping techniques Y1 - 2010 N1 - abstract ; IV International Symposium on Modelling of Physiological Flows, Sardinia, Italy, June 02-05, 2010 ; MPF2010 ER - TY - JOUR A1 - Jayaraman, Chandrasekaran A1 - Mummidisetty, Chaitanya Krishna A1 - Loesch, Alexandra A1 - Kaur, Sandi A1 - Hoppe-Ludwig, Shenan A1 - Staat, Manfred A1 - Jayaraman, Arun T1 - Postural and metabolic benefits of using a forearm support walker in older adults with impairments JF - Archives of Physical Medicine and Rehabilitation Y1 - 2019 U6 - https://doi.org/10.1016/j.apmr.2018.10.001 SN - 0003-9993 VL - Volume 100 IS - Issue 4 SP - 638 EP - 647 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jiminez German, Salvador A1 - Behbahani, Mehdi A1 - Miettinen, Susanna A1 - Grijpma, Dirk W. A1 - Haimi, Suvi P. T1 - Proliferation and differentiation of adipose stem cells towards smooth muscle cells on poly(trimethylene carbonate) membranes JF - Macromolecular symposia Y1 - 2013 SN - 0258-0322 VL - Vol. 334 IS - Iss. 1 SP - 133 EP - 142 PB - Wiley CY - Weinheim 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 - Müller, Wolfram A1 - Staat, Manfred T1 - Optimization of the flight technique in ski jumping: the influence of wind Y1 - 2019 U6 - https://doi.org/10.1016/j.jbiomech.2019.03.023 IS - Early view PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Jung, Alexander A1 - Staat, Manfred T1 - Erratum to "Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue" [GAMM-Mitteilungen, (2019), 42, 4, 10.1002/gamm.201900002] JF - GAMM-Mitteilungen Y1 - 2020 U6 - https://doi.org/10.1002/gamm.202000011 SN - 1522-2608 N1 - Refers to: Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue. Alexander Jung, Manfred Staat. Volume 42, Issue 4. GAMM-Mitteilungen, 2019. https://doi.org/10.1002/gamm.201900002 VL - 43 IS - 4 PB - Wiley-VCH GmbH CY - Weinheim ER - TY - JOUR A1 - Jung, Alexander A1 - Staat, Manfred T1 - Modeling and simulation of human induced pluripotent stem cell-derived cardiac tissue JF - GAMM - Mitteilungen der Gesellschaft für Angewandte Mathematik und Mechanik Y1 - 2019 U6 - https://doi.org/10.1002/gamm.201900002 SN - 1522-2608 VL - 42 IS - 4 PB - Wiley CY - Weinheim 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 - Jung, Alexander A1 - Staat, Manfred A1 - Müller, Wolfram T1 - Flight style optimization in ski jumping on normal, large, and ski flying hills JF - Journal of biomechanics Y1 - 2013 SN - 1873-2380 (E-Journal); 0021-9290 (Print) N1 - Corrigendum to “Flight style optimization in ski jumping on normal, large, and ski flying hills” [J. Biomech 47 (2014) 716-722] Journal of Biomechanics, 2018;71:313. VL - Vol. 47 IS - Iss. 3 SP - 716 EP - 722 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Karamanidis, Kiros A1 - Albracht, Kirsten A1 - Braunstein, Bjoern A1 - Catala, Maria Moreno A1 - Goldmann, Jan-Peter A1 - Brüggemann, Gert-Peter T1 - Lower leg musculoskeletal geometry and sprint performance JF - Gait and Posture N2 - The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components. Y1 - 2011 U6 - https://doi.org/10.1016/j.gaitpost.2011.03.009 SN - 0966-6362 VL - 34 IS - 1 SP - 138 EP - 141 PB - Elsevier CY - Amsterdam 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 - Ketelhut, Maike A1 - Brügge, G. M. A1 - Göll, Fabian A1 - Braunstein, Bjoern A1 - Albracht, Kirsten A1 - Abel, Dirk T1 - Adaptive iterative learning control of an industrial robot during neuromuscular training JF - IFAC PapersOnLine N2 - To prevent the reduction of muscle mass and loss of strength coming along with the human aging process, regular training with e.g. a leg press is suitable. However, the risk of training-induced injuries requires the continuous monitoring and controlling of the forces applied to the musculoskeletal system as well as the velocity along the motion trajectory and the range of motion. In this paper, an adaptive norm-optimal iterative learning control algorithm to minimize the knee joint loadings during the leg extension training with an industrial robot is proposed. The response of the algorithm is tested in simulation for patients with varus, normal and valgus alignment of the knee and compared to the results of a higher-order iterative learning control algorithm, a robust iterative learning control and a recently proposed conventional norm-optimal iterative learning control algorithm. Although significant improvements in performance are made compared to the conventional norm-optimal iterative learning control algorithm with a small learning factor, for the developed approach as well as the robust iterative learning control algorithm small steady state errors occur. KW - Iterative learning control KW - Robotic rehabilitation KW - Adaptive control Y1 - 2020 U6 - https://doi.org/10.1016/j.ifacol.2020.12.741 SN - 2405-8963 VL - 53 IS - 2 SP - 16468 EP - 16475 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Ketelhut, Maike A1 - Göll, Fabian A1 - Braunstein, Björn A1 - Albracht, Kirsten A1 - Abel, Dirk T1 - Comparison of different training algorithms for the leg extension training with an industrial robot JF - Current Directions in Biomedical Engineering N2 - In the past, different training scenarios have been developed and implemented on robotic research platforms, but no systematic analysis and comparison have been done so far. This paper deals with the comparison of an isokinematic (motion with constant velocity) and an isotonic (motion against constant weight) training algorithm. Both algorithms are designed for a robotic research platform consisting of a 3D force plate and a high payload industrial robot, which allows leg extension training with arbitrary six-dimensional motion trajectories. In the isokinematic as well as the isotonic training algorithm, individual paths are defined i n C artesian s pace by sufficient s upport p oses. I n t he i sotonic t raining s cenario, the trajectory is adapted to the measured force as the robot should only move along the trajectory as long as the force applied by the user exceeds a minimum threshold. In the isotonic training scenario however, the robot’s acceleration is a function of the force applied by the user. To validate these findings, a simulative experiment with a simple linear trajectory is performed. For this purpose, the same force path is applied in both training scenarios. The results illustrate that the algorithms differ in the force dependent trajectory adaption. KW - Rehabilitation Technology and Prosthetics KW - Surgical Navigation and Robotics Y1 - 2018 U6 - https://doi.org/10.1515/cdbme-2018-0005 SN - 2364-5504 VL - 4 IS - 1 SP - 17 EP - 20 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Ketelhut, Maike A1 - Kolditz, Melanie A1 - Göll, Fabian A1 - Braunstein, Bjoern A1 - Albracht, Kirsten A1 - Abel, Dirk T1 - Admittance control of an industrial robot during resistance training JF - IFAC-PapersOnLine N2 - Neuromuscular strength training of the leg extensor muscles plays an important role in the rehabilitation and prevention of age and wealth related diseases. In this paper, we focus on the design and implementation of a Cartesian admittance control scheme for isotonic training, i.e. leg extension and flexion against a predefined weight. For preliminary testing and validation of the designed algorithm an experimental research and development platform consisting of an industrial robot and a force plate mounted at its end-effector has been used. Linear, diagonal and arbitrary two-dimensional motion trajectories with different weights for the leg extension and flexion part are applied. The proposed algorithm is easily adaptable to trajectories consisting of arbitrary six-dimensional poses and allows the implementation of individualized trajectories. KW - Assistive technology KW - Rehabilitation engineering KW - Human-Computer interaction KW - Automatic control Y1 - 2019 U6 - https://doi.org/10.1016/j.ifacol.2019.12.102 SN - 2405-8963 N1 - 14th IFAC Symposium on Analysis, Design, and Evaluation of Human Machine Systems HMS 2019 Tallinn, Estonia, 16–91 September 2019 VL - 52 IS - 19 SP - 223 EP - 228 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kezerashvili, Roman Ya A1 - Dachwald, Bernd T1 - Preface: Solar sailing: Concepts, technology, and missions II JF - Advances in Space Research Y1 - 2021 U6 - https://doi.org/10.1016/j.asr.2021.01.037 SN - 0273-1177 VL - 67 IS - 9 SP - 2559 EP - 2560 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Knox, Ronald A1 - Bruggemann, Andrea A1 - Gossmann, Matthias A1 - Thomas, Ulrich A1 - Horváth, András A1 - Dragicevic, Elena A1 - Stoelzle-Feix, Sonja A1 - Fertig, Niels A1 - Jung, Alexander A1 - Raman, Aravind Hariharan A1 - Staat, Manfred A1 - Linder, Peter T1 - Combining physiological relevance and throughput for in vitro cardiac contractility measurement JF - Biophysical Journal N2 - Despite increasing acceptance of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in safety pharmacology, controversy remains about the physiological relevance of existing in vitro models for their mechanical testing. We hypothesize that existing signs of immaturity of the cell models result from an improper mechanical environment. We cultured hiPSC-CMs in a 96-well format on hyperelastic silicone membranes imitating their native mechanical environment, resulting in physiological responses to compound stimuli.We validated cell responses on the FLEXcyte 96, with a set of reference compounds covering a broad range of cellular targets, including ion channel modulators, adrenergic receptor modulators and kinase inhibitors. Acute (10 - 30 min) and chronic (up to 7 days) effects were investigated. Furthermore, the measurements were complemented with electromechanical models based on electrophysiological recordings of the used cell types.hiPSC-CMs were cultured on freely-swinging, ultra-thin and hyperelastic silicone membranes. The weight of the cell culture medium deflects the membranes downwards. Rhythmic contraction of the hiPSC-CMs resulted in dynamic deflection changes which were quantified by capacitive distance sensing. The cells were cultured for 7 days prior to compound addition. Acute measurements were conducted 10-30 minutes after compound addition in standard culture medium. For chronic treatment, compound-containing medium was replaced daily for up to 7 days. Electrophysiological properties of the employed cell types were recorded by automated patch-clamp (Patchliner) and the results were integrated into the electromechanical model of the system.Calcium channel agonist S Bay K8644 and beta-adrenergic stimulator isoproterenol induced significant positive inotropic responses without additional external stimulation. Kinase inhibitors displayed cardiotoxic effects on a functional level at low concentrations. The system-integrated analysis detected alterations in beating shape as well as frequency and arrhythmic events and we provide a quantitative measure of these. Y1 - 2020 U6 - https://doi.org/10.1016/j.bpj.2019.11.3104 SN - 0006-3495 N1 - Raman, Arayind Hariharan im Artikel unter dem Namen: Raman, Alexander H. VL - 118 IS - Issue 3, Supplement 1 SP - 570a PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Kodomskoi, Leonid A1 - Kotliar, Konstantin A1 - Schröder, Andreas A1 - Weiss, Michael A1 - Hille, Konrad T1 - Suture-Probe Canaloplasty as an Alternative to Canaloplasty using the iTrack™ Microcatheter JF - Journal of Glaucoma Y1 - 2019 U6 - https://doi.org/10.1097/IJG.0000000000001321 SN - 1057-0829 IS - Epub ahead of print PB - Lippincott Williams & Wilkins CY - Philadelphia ER - TY - JOUR A1 - Kolditz, Melanie A1 - Albin, Thivaharan A1 - Abel, Dirk A1 - Fasse, Alessandro A1 - Brüggemann, Gert-Peter A1 - Albracht, Kirsten T1 - Evaluation of foot position and orientation as manipulated variables to control external knee adduction moments in leg extension training JF - Computer methods and programs in biomedicine N2 - Background and Objective Effective leg extension training at a leg press requires high forces, which need to be controlled to avoid training-induced damage. In order to avoid high external knee adduction moments, which are one reason for unphysiological loadings on knee joint structures, both training movements and the whole reaction force vector need to be observed. In this study, the applicability of lateral and medial changes in foot orientation and position as possible manipulated variables to control external knee adduction moments is investigated. As secondary parameters both the medio-lateral position of the center of pressure and the frontal-plane orientation of the reaction force vector are analyzed. Methods Knee adduction moments are estimated using a dynamic model of the musculoskeletal system together with the measured reaction force vector and the motion of the subject by solving the inverse kinematic and dynamic problem. Six different foot conditions with varying positions and orientations of the foot in a static leg press are evaluated and compared to a neutral foot position. Results Both lateral and medial wedges under the foot and medial and lateral shifts of the foot can influence external knee adduction moments in the presented study with six healthy subjects. Different effects are observed with the varying conditions: the pose of the leg is changed and the direction and center of pressure of the reaction force vector is influenced. Each effect results in a different direction or center of pressure of the reaction force vector. Conclusions The results allow the conclusion that foot position and orientation can be used as manipulated variables in a control loop to actively control knee adduction moments in leg extension training. KW - External knee adduction moments KW - Manipulated variables KW - Inverse dynamic problem KW - Inverse kinematic problem KW - Musculoskeletal model Y1 - 2016 U6 - https://doi.org/10.1016/j.cmpb.2016.09.005 SN - 0169-2607 N1 - Part of special issue: "SI: Personalised Models and System Identification" VL - 171 SP - 81 EP - 86 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Konstantinidis, Konstantinos A1 - Flores Martinez, Claudio A1 - Dachwald, Bernd A1 - Ohndorf, Andreas A1 - Dykta, Paul A1 - Bowitz, Pascal A1 - Rudolph, Martin A1 - Digel, Ilya A1 - Kowalski, Julia A1 - Voigt, Konstantin A1 - Förstner, Roger T1 - A lander mission to probe subglacial water on Saturn's moon enceladus for life JF - Acta astronautica Y1 - 2015 SN - 1879-2030 (E-Journal); 0094-5765 (Print) VL - Vol. 106 SP - 63 EP - 89 PB - Elsevier CY - Amsterdam ER -