TY - CHAP A1 - Jung, Alexander A1 - Frotscher, Ralf A1 - Staat, Manfred T1 - Electromechanical model of hiPSC-derived ventricular cardiomyocytes cocultured with fibroblasts T2 - 6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK N2 - The CellDrum provides an experimental setup to study the mechanical effects of fibroblasts co-cultured with hiPSC-derived ventricular cardiomyocytes. Multi-scale computational models based on the Finite Element Method are developed. Coupled electrical cardiomyocyte-fibroblast models (cell level) are embedded into reaction-diffusion equations (tissue level) which compute the propagation of the action potential in the cardiac tissue. Electromechanical coupling is realised by an excitation-contraction model (cell level) and the active stress arising during contraction is added to the passive stress in the force balance, which determines the tissue displacement (tissue level). Tissue parameters in the model can be identified experimentally to the specific sample. Y1 - 2018 ER - TY - CHAP A1 - Jung, Alexander A1 - Staat, Manfred A1 - Müller, Wolfram T1 - Effect of wind on flight style optimisation in ski jumping T2 - 15th International Symposium on Computer Simulation in Biomechanics ; July 9th-11th 2015, Edinburgh, UK Y1 - 2016 SP - 53 EP - 54 PB - The University of Edinburgh ; Loughborough University CY - Edinburgh ER - TY - CHAP A1 - Hunker, Jan A1 - Jung, Alexander A1 - Goßmann, Matthias A1 - Linder, Peter A1 - Staat, Manfred ED - Staat, Manfred ED - Erni, Daniel T1 - Development of a tool to analyze the conduction speed in microelectrode array measurements of cardiac tissue T2 - 3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen N2 - The discovery of human induced pluripotent stem cells reprogrammed from somatic cells [1] and their ability to differentiate into cardiomyocytes (hiPSC-CMs) has provided a robust platform for drug screening [2]. Drug screenings are essential in the development of new components, particularly for evaluating the potential of drugs to induce life-threatening pro-arrhythmias. Between 1988 and 2009, 14 drugs have been removed from the market for this reason [3]. The microelectrode array (MEA) technique is a robust tool for drug screening as it detects the field potentials (FPs) for the entire cell culture. Furthermore, the propagation of the field potential can be examined on an electrode basis. To analyze MEA measurements in detail, we have developed an open-source tool. Y1 - 2019 SN - 978-3-940402-22-6 U6 - http://dx.doi.org/10.17185/duepublico/48750 SP - 7 EP - 8 PB - Universität Duisburg-Essen CY - Duisburg ER - TY - CHAP A1 - Mueller, Wolfram A1 - Jung, Alexander A1 - Schmölzer, Bernhard ED - Faulhaber, Martin ED - Schobersberger, Wolfgang ED - Schobersberger, Beatrix ED - Sumann, Günther ED - Domej, Wolfgang T1 - Der Einfluss der Höhe über dem Meeresspiegel auf die Flugbahnen im Schispringen T1 - The influence of altitude on the flight paths in ski jumping T2 - Jahrbuch 2015 - Österreichische Gesellschaft für Alpin- und Höhenmedizin Y1 - 2015 SN - 978-3-9501312-5-3 SP - 173 EP - 190 PB - Österreichische Gesellschaft für Alpin- und Höhenmedizin CY - Innsbruck ER - TY - GEN A1 - Jung, Alexander A1 - Müller, Wolfram A1 - Staat, Manfred T1 - Corrigendum to “Wind and fairness in ski jumping: A computer modelling analysis” [J. Biomech. 75 (2018) 147–153] T2 - Journal of Biomechanics Y1 - 2021 U6 - http://dx.doi.org/10.1016/j.jbiomech.2021.110690 SN - 0021-9290 N1 - Refers to: Alexander Jung, Wolfram Müller, Manfred Staat: Wind and fairness in ski jumping: A computer modelling analysis. Journal of Biomechanics, Volume 75. 25 June 2018. Pages 147-153. https://doi.org/10.1016/j.jbiomech.2018.05.001 VL - 128 IS - Article number: 110690 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 - http://dx.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 - CHAP A1 - Jung, Alexander A1 - Staat, Manfred ED - Erni, Daniel T1 - Computing olympic gold: Ski jumping as an example T2 - 1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen Y1 - 2016 SN - 978-3-940402-06-6 U6 - http://dx.doi.org/10.17185/duepublico/40821 SP - 54 EP - 55 PB - Universität Duisburg-Essen CY - Duisburg 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 - http://dx.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 - Abel, Alexander A1 - Kahmann, Stephanie Lucina A1 - Mellon, Stephen A1 - Staat, Manfred A1 - Jung, Alexander T1 - An open-source tool for the validation of finite element models using three-dimensional full-field measurements JF - Medical Engineering & Physics N2 - Three-dimensional (3D) full-field measurements provide a comprehensive and accurate validation of finite element (FE) models. For the validation, the result of the model and measurements are compared based on two respective point-sets and this requires the point-sets to be registered in one coordinate system. Point-set registration is a non-convex optimization problem that has widely been solved by the ordinary iterative closest point algorithm. However, this approach necessitates a good initialization without which it easily returns a local optimum, i.e. an erroneous registration. The globally optimal iterative closest point (Go-ICP) algorithm has overcome this drawback and forms the basis for the presented open-source tool that can be used for the validation of FE models using 3D full-field measurements. The capability of the tool is demonstrated using an application example from the field of biomechanics. Methodological problems that arise in real-world data and the respective implemented solution approaches are discussed. Y1 - 2020 U6 - http://dx.doi.org/10.1016/j.medengphy.2019.10.015 SN - 1350-4533 VL - 77 SP - 125 EP - 129 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Müller, Wolfram A1 - Jung, Alexander A1 - Ahammer, Helmut T1 - Advantages and problems of nonlinear methods applied to analyze physiological time signals: human balance control as an example JF - Scientific Reports Y1 - 2017 SN - 2045-2322 U6 - http://dx.doi.org/10.1038/s41598-017-02665-5 VL - 7 IS - Article number 2464 SP - 1 EP - 11 PB - Springer Nature CY - Cham ER -