@article{JungMuellerStaat2019, author = {Jung, Alexander and M{\"u}ller, Wolfram and Staat, Manfred}, title = {Optimization of the flight technique in ski jumping: the influence of wind}, number = {Early view}, publisher = {Elsevier}, address = {Amsterdam}, doi = {10.1016/j.jbiomech.2019.03.023}, year = {2019}, language = {en} } @inproceedings{RamanJungHorvathetal.2019, author = {Raman, Aravind Hariharan and Jung, Alexander and Horv{\´a}th, Andr{\´a}s and Becker, Nadine and Staat, Manfred}, title = {Modification of a computer model of human stem cell-derived cardiomyocyte electrophysiology based on Patch-Clamp measurements}, series = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, booktitle = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, editor = {Staat, Manfred and Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-22-6}, doi = {10.17185/duepublico/48750}, pages = {10 -- 11}, year = {2019}, abstract = {Human induced pluripotent stem cells (hiPSCs) have shown to be promising in disease studies and drug screenings [1]. Cardiomyocytes derived from hiPSCs have been extensively investigated using patch-clamping and optical methods to compare their electromechanical behaviour relative to fully matured adult cells. Mathematical models can be used for translating findings on hiPSCCMs to adult cells [2] or to better understand the mechanisms of various ion channels when a drug is applied [3,4]. Paci et al. (2013) [3] developed the first model of hiPSC-CMs, which they later refined based on new data [3]. The model is based on iCells® (Fujifilm Cellular Dynamics, Inc. (FCDI), Madison WI, USA) but major differences among several cell lines and even within a single cell line have been found and motivate an approach for creating sample-specific models. We have developed an optimisation algorithm that parameterises the conductances (in S/F=Siemens/Farad) of the latest Paci et al. model (2018) [5] using current-voltage data obtained in individual patch-clamp experiments derived from an automated patch clamp system (Patchliner, Nanion Technologies GmbH, Munich).}, language = {en} } @article{HorbachDuongStaat2017, author = {Horbach, Andreas and Duong, Minh Tuan and Staat, Manfred}, title = {Modelling of compressible and orthotropic surgical mesh implants based on optical deformation measurement}, series = {Journal of the mechanical behavior of biomedical materials}, volume = {74}, journal = {Journal of the mechanical behavior of biomedical materials}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1751-6161}, doi = {10.1016/j.jmbbm.2017.06.012}, pages = {400 -- 410}, year = {2017}, language = {en} } @article{DuongNguyenStaat2015, author = {Duong, Minh Tuan and Nguyen, Nhu Huynh and Staat, Manfred}, title = {Physical response of hyperelastic models for composite materials and soft tissues}, series = {Asia pacific journal on computational engineering}, volume = {2}, journal = {Asia pacific journal on computational engineering}, number = {3 (December 2015)}, issn = {2196-1166}, doi = {10.1186/s40540-015-0015-x}, pages = {1 -- 18}, year = {2015}, language = {en} } @article{StaatHeitzer1999, author = {Staat, Manfred and Heitzer, M.}, title = {FEM-computation of load carrying capacity of highly loaded passive components by direct methods. Heitzer, M. ; Staat, M.}, series = {Nuclear Engineering and Design. 193 (1999), H. 3}, journal = {Nuclear Engineering and Design. 193 (1999), H. 3}, isbn = {0029-5493}, pages = {349 -- 358}, year = {1999}, language = {en} } @incollection{BhattaraiStaat2018, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Mechanics of soft tissue reactions to textile mesh implants}, series = {Biological, Physical and Technical Basics of Cell Engineering}, booktitle = {Biological, Physical and Technical Basics of Cell Engineering}, editor = {Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l and Zhubanova, Azhar A. and Digel, Ilya}, publisher = {Springer}, address = {Singapore}, isbn = {978-981-10-7904-7}, doi = {10.1007/978-981-10-7904-7_11}, pages = {251 -- 275}, year = {2018}, abstract = {For pelvic floor disorders that cannot be treated with non-surgical procedures, minimally invasive surgery has become a more frequent and safer repair procedure. More than 20 million prosthetic meshes are implanted each year worldwide. The simple selection of a single synthetic mesh construction for any level and type of pelvic floor dysfunctions without adopting the design to specific requirements increase the risks for mesh related complications. Adverse events are closely related to chronic foreign body reaction, with enhanced formation of scar tissue around the surgical meshes, manifested as pain, mesh erosion in adjacent structures (with organ tissue cut), mesh shrinkage, mesh rejection and eventually recurrence. Such events, especially scar formation depend on effective porosity of the mesh, which decreases discontinuously at a critical stretch when pore areas decrease making the surgical reconstruction ineffective that further augments the re-operation costs. The extent of fibrotic reaction is increased with higher amount of foreign body material, larger surface, small pore size or with inadequate textile elasticity. Standardized studies of different meshes are essential to evaluate influencing factors for the failure and success of the reconstruction. Measurements of elasticity and tensile strength have to consider the mesh anisotropy as result of the textile structure. An appropriate mesh then should show some integration with limited scar reaction and preserved pores that are filled with local fat tissue. This chapter reviews various tissue reactions to different monofilament mesh implants that are used for incontinence and hernia repairs and study their mechanical behavior. This helps to predict the functional and biological outcomes after tissue reinforcement with meshes and permits further optimization of the meshes for the specific indications to improve the success of the surgical treatment.}, language = {en} } @inproceedings{NixFrotscherStaat2012, author = {Nix, Yvonne and Frotscher, Ralf and Staat, Manfred}, title = {Implementation of the edge-based smoothed extended finite element method}, series = {Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012}, booktitle = {Proceedings 6th European Congress on Computational Methods in Applied Sciences and Engineering (ECCOMAS 2012) Vienna, Austria, September 10-14, 2012}, editor = {Eberhardsteiner, J.}, year = {2012}, language = {en} } @article{TranStaat2010, author = {Tran, Thanh Ngoc and Staat, Manfred}, title = {Shakedown analysis of two dimensional structures by an edge-based smoothed finite element method}, pages = {1 -- 7}, year = {2010}, language = {en} } @article{LeschingerBeschAydinetal.2019, author = {Leschinger, Tim and Besch, Katharina and Aydin, Cansu and Staat, Manfred and Scaal, Martin and M{\"u}ller, Lars Peter and Wegmann, Kilian}, title = {Irreparable rotator cuff tears: a biomechanical comparison of superior capsuloligamentous complex reconstruction techniques and an interposition graft technique}, series = {The Orthopaedic Journal of Sports Medicine}, volume = {7}, journal = {The Orthopaedic Journal of Sports Medicine}, number = {8}, doi = {10.1177/2325967119864590}, pages = {1 -- 5}, year = {2019}, language = {en} } @inproceedings{PhamNguyenStaat2012, author = {Pham, Phu Tinh and Nguyen, Thanh Ngoc and Staat, Manfred}, title = {FEM based shakedown analysis of hardening structures}, series = {Proceedings International Conference on Advances in Computational Mechanics (ACOME)}, booktitle = {Proceedings International Conference on Advances in Computational Mechanics (ACOME)}, pages = {870 -- 882}, year = {2012}, language = {en} } @article{TranStaat2020, author = {Tran, Ngoc Trinh and Staat, Manfred}, title = {Direct plastic structural design under lognormally distributed strength by chance constrained programming}, series = {Optimization and Engineering}, volume = {21}, journal = {Optimization and Engineering}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {1573-2924}, doi = {10.1007/s11081-019-09437-2}, pages = {131 -- 157}, year = {2020}, abstract = {We propose the so-called chance constrained programming model of stochastic programming theory to analyze limit and shakedown loads of structures under random strength with a lognormal distribution. A dual chance constrained programming algorithm is developed to calculate simultaneously both the upper and lower bounds of the plastic collapse limit and the shakedown limit. The edge-based smoothed finite element method (ES-FEM) is used with three-node linear triangular elements.}, language = {en} } @article{Staat2012, author = {Staat, Manfred}, title = {Limit and shakedown analysis under uncertainty}, series = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, volume = {19}, journal = {Tap chi Khoa hoc \& ung dung - Dai hoc Ton Duc Thang}, pages = {45 -- 47}, year = {2012}, language = {en} } @article{LeversStaatLaack2016, author = {Levers, A. and Staat, Manfred and Laack, Walter van}, title = {Analysis of the long-term effect of the MBST® nuclear magnetic resonance therapy on gonarthrosis}, series = {Orthopedic Practice}, volume = {47}, journal = {Orthopedic Practice}, number = {11}, pages = {521 -- 528}, year = {2016}, language = {en} } @inproceedings{BhattaraiStaat2016, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Female pelvic floor dysfunction: progress weakening of the support system}, series = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, booktitle = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, editor = {Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, doi = {10.17185/duepublico/40821}, pages = {11 -- 12}, year = {2016}, abstract = {The structure of the female pelvic floor (PF) is an inter-related system of bony pelvis,muscles, pelvic organs, fascias, ligaments, and nerves with multiple functions. Mechanically, thepelvic organ support system are of two types: (I) supporting system of the levator ani (LA) muscle,and (II) the suspension system of the endopelvic fascia condensation [1], [2]. Significantdenervation injury to the pelvic musculature, depolimerization of the collagen fibrils of the softvaginal hammock, cervical ring and ligaments during pregnancy and vaginal delivery weakens thenormal functions of the pelvic floor. Pelvic organ prolapse, incontinence, sexual dysfunction aresome of the dysfunctions which increases progressively with age and menopause due toweakened support system according to the Integral theory [3]. An improved 3D finite elementmodel of the female pelvic floor as shown in Fig. 1 is constructed that: (I) considers the realisticsupport of the organs to the pelvic side walls, (II) employs the improvement of our previous FEmodel [4], [5] along with the patient based geometries, (III) incorporates the realistic anatomy andboundary conditions of the endopelvic (pubocervical and rectovaginal) fascia, and (IV) considersvarying stiffness of the endopelvic fascia in the craniocaudal direction [3]. Several computationsare carried out on the presented computational model with healthy and damaged supportingtissues, and comparisons are made to understand the physiopathology of the female PF disorders.}, language = {en} } @article{UllrichGrottkeRossaintetal.2010, author = {Ullrich, Sebastian and Grottke, Oliver and Rossaint, Rolf and Staat, Manfred and Deserno, Thomas M. and Kuhlen, Torsten}, title = {Virtual Needle Simulation with Haptics for Regional Anaesthesia}, pages = {1 -- 3}, year = {2010}, language = {en} } @inproceedings{KahmannHacklWegmannetal.2016, author = {Kahmann, Stephanie and Hackl, Michael and Wegmann, Kilian and M{\"u}ller, Lars-Peter and Staat, Manfred}, title = {Impact of a proximal radial shortening osteotomy on the distribution of forces and the stability of the elbow}, series = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, booktitle = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, editor = {Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, doi = {10.17185/duepublico/40821}, pages = {7 -- 8}, year = {2016}, abstract = {The human arm consists of the humerus (upper arm), the medial ulna and the lateral radius (forearm). The joint between the humerus and the ulna is called humeroulnar joint and the joint between the humerus and the radius is called humeroradial joint. Lateral and medial collateral ligaments stabilize the elbow. Statistically, 2.5 out of 10,000 people suffer from radial head fractures [1]. In these fractures the cartilage is often affected. Caused by the injured cartilage, degenerative diseases like posttraumatic arthrosis may occur. The resulting pain and reduced range of motion have an impact on the patient's quality of life. Until now, there has not been a treatment which allows typical loads in daily life activities and offers good long-term results. A new surgical approach was developed with the motivation to reduce the progress of the posttraumatic arthrosis. Here, the radius is shortened by 3 mm in the proximal part [2]. By this means, the load of the radius is intended to be reduced due to a load shift to the ulna. Since the radius is the most important stabilizer of the elbow it has to be confirmed that the stability is not affected. In the first test (Fig. 1 left), pressure distributions within the humeroulnar and humeroradial joints a native and a shortened radius were measured using resistive pressure sensors (I5076 and I5027, Tekscan, USA). The humerus was loaded axially in a tension testing machine (Z010, Zwick Roell, Germany) in 50 N steps up to 400 N. From the humerus the load is transmitted through both the radius and the ulna into the hand which is fixed on the ground. In the second test (Fig. 1 right), the joint stability was investigated using a digital image correlation system to measure the displacement of the ulna. Here, the humerus is fixed with a desired flexion angle and the unconstrained forearm lies on the ground. A rope connects the load actuator with a hook fixed in the ulna. A guide roller is used so that the rope pulls the ulna horizontally when a tensile load is applied. This creates a moment about the elbow joint with a maximum value of 7.5 Nm. Measurements were performed with varying flexion angles (0°, 30°, 60°, 90°, 120°). For both tests and each measurement, seven specimens were used. Student's t-test was employed to determine whether the mean values of the measurements in native specimen and operated specimens differ significantly.}, language = {en} } @article{CiobanuStaatRahimi2008, author = {Ciobanu, Octavian and Staat, Manfred and Rahimi, Alireza}, title = {The use of open source software in biomechanical finite element analysis}, series = {Buletinul Institutului Politehnic din Ia{\c{s}}i / Universitatea Tehnică Gh. Asachi, Ia{\c{s}}i Secţia 5, Construcţii de ma{\c{s}}ini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta}, volume = {54}, journal = {Buletinul Institutului Politehnic din Ia{\c{s}}i / Universitatea Tehnică Gh. Asachi, Ia{\c{s}}i Secţia 5, Construcţii de ma{\c{s}}ini = Machine construction = Bulletin of the Polytechnic Institute of Jassy = Izvestija Jasskogo Politechničeskogo Instituta}, number = {7/8}, issn = {1011-2855}, pages = {213 -- 220}, year = {2008}, language = {en} } @book{StaatHeitzerYanetal.2000, author = {Staat, Manfred and Heitzer, M. and Yan, Ai-Min and Khoi, Vu Duc and Nguyen, Dang Hung and Valdoire, F. and Lahousse, A.}, title = {Limit Analysis of Defects}, publisher = {Forschungszentrum J{\"u}lich}, address = {J{\"u}lich}, issn = {0944-2952}, pages = {89 S.}, year = {2000}, language = {en} } @article{Staat1996, author = {Staat, Manfred}, title = {Probabilistic assessment of the fracture mechanics behaviour of an HTR-module primary circuit pressure boundary}, series = {Nuclear Engineering and Design. 160 (1996), H. 1-2}, journal = {Nuclear Engineering and Design. 160 (1996), H. 1-2}, isbn = {0029-5493}, pages = {221 -- 236}, year = {1996}, language = {en} } @article{StaatHeitzer2000, author = {Staat, Manfred and Heitzer, M.}, title = {Reliability Analysis of Elasto-Plastic Structures under Variable Loads}, series = {Inelastic analysis of structures under variable loads : theory and engineering applications / Maier, G.; Weichert, D. [ed]}, journal = {Inelastic analysis of structures under variable loads : theory and engineering applications / Maier, G.; Weichert, D. [ed]}, publisher = {Kluwer Academic Publ.}, address = {Dordrecht}, isbn = {0-7923-6645-X}, pages = {269 -- 288}, year = {2000}, language = {en} }