TY - JOUR A1 - Fischer, Sophie A1 - Ehrig, Rainald A1 - Schäfer, Stefan A1 - Tronci, Enrico A1 - Mancini, Toni A1 - Egli, Marcel A1 - Ille, Fabian A1 - Krüger, Tillmann H. C. A1 - Leeners, Brigitte A1 - Röblitz, Susanna T1 - Mathematical Modelling and Simulation Provides Evidence for New Strategies of Ovarian Stimulation JF - Frontiers in Endocrinology N2 - New approaches to ovarian stimulation protocols, such as luteal start, random start or double stimulation, allow for flexibility in ovarian stimulation at different phases of the menstrual cycle which is especially useful when time for assisted reproductive technology is limited, e.g. for emergency fertility preservation in cancer patients. It has been proposed that the success of these methods is based on the continuous growth of multiple cohorts ("waves") of follicles throughout the menstrual cycle which leads to the availability of ovarian follicles for ovarian controlled stimulation at several time points. Though several preliminary studies have been published, their scientific evidence has not been considered as being strong enough to integrate these results into routine clinical practice. This work aims at adding further scientific evidence about the efficiency of variable-start protocols and underpinning the theory of follicular waves by using mathematical modelling and numerical simulations. For this purpose, we have modified and coupled two previously published models, one describing the time course of hormones and one describing competitive follicular growth in a normal menstrual cycle. The coupled model is used to test stimulation protocols in silico. Simulation results show the occurrence of follicles in a wave-like manner during a normal menstrual cycle and qualitatively predict the outcome of ovarian stimulation initiated at different time points of the menstrual cycle. Y1 - 2021 U6 - https://doi.org/10.3389/fendo.2021.613048 VL - 12 ER - TY - CHAP A1 - Mancini, Toni A1 - Mari, Federico A1 - Massini, Annalisa A1 - Melatti, Igor A1 - Salvo, Ivano A1 - Sinisi, Stefano A1 - Tronci, Enrico A1 - Ehrig, Rainald A1 - Röblitz, Susanna A1 - Leeners, Brigitte T1 - Computing Personalised Treatments through In Silico Clinical Trials. A Case Study on Downregulation in Assisted Reproduction T2 - Experimental Evaluation of Algorithms for Solving Problems with Combinatorial Explosion, Workshop of the Federated Logic Conference 2018 (FLoC 2018), Oxford N2 - In Silico Clinical Trials (ISCT), i.e., clinical experimental campaigns carried out by means of computer simulations, hold the promise to decrease time and cost for the safety and efficacy assessment of pharmacological treatments, reduce the need for animal and human testing, and enable precision medicine. In this paper we present a case study aiming at quantifying, by means of a multi-arm ISCT supervised by intelligent search, the potential impact of precision medicine approaches on a real pharmacological treatment, namely the downregulation phase of a complex clinical protocol for assisted reproduction. Y1 - 2018 U6 - https://doi.org/10.29007/g864 SP - 1 EP - 16 ER - TY - GEN A1 - Ehrig, Rainald A1 - Dierkes, Thomas A1 - Schäfer, Stefan A1 - Röblitz, Susanna A1 - Tronci, Enrico A1 - Mancini, Toni A1 - Salvo, Ivano A1 - Alimguzhin, Vadim A1 - Mari, Federico A1 - Melatti, Igor A1 - Massini, Annalisa A1 - Krüger, Tillmann H. C. A1 - Egli, Marcel A1 - Ille, Fabian A1 - Leeners, Brigitte T1 - An Integrative Approach for Model Driven Computation of Treatments in Reproductive Medicine N2 - We present an overview of the current status of the European collaborative project PAEON. The challenge of PAEON is to provide specialists in reproduc- tive medicine with a computerised model of the menstrual cycle under normal and various pathological conditions, which will allow them to get further in- sight in fertility dynamics. This model also enables the simulation of treatment protocols, which were used within in vitro fertilization. By the definition of virtual patients through biologically admissible parametrizations our approach allows not only the evaluation of a given treatment strategy in silico, but also the design and optimization of such protocols. Once a protocol is formalized in the virtual hospital, the success can be controlled by a treatment execution monitor, which works then as a clinical decision support system. All these tools will be combined in a virtual hospital environment, enabling the access to the PAEON services through the web. T3 - ZIB-Report - 16-04 Y1 - 2016 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:0297-zib-57103 SN - 1438-0064 ER - TY - CHAP A1 - Ehrig, Rainald A1 - Dierkes, Thomas A1 - Schäfer, Stefan A1 - Röblitz, Susanna A1 - Tronci, Enrico A1 - Mancini, Toni A1 - Salvo, Ivano A1 - Alimguzhin, Vadim A1 - Mari, Federico A1 - Melatti, Igor A1 - Massini, Annalisa A1 - Krüger, Tillmann H. C. A1 - Egli, Marcel A1 - Ille, Fabian A1 - Leeners, Brigitte T1 - An integrative approach for model driven computation of treatments in reproductive medicine T2 - BIOMAT - Proceedings of the 15th International Symposium on Mathematical and Computational Biology, Rorkee, India Y1 - 2016 ER - TY - CHAP A1 - Mancini, Toni A1 - Salvo, Ivano A1 - Mari, Federico A1 - Melatti, Igor A1 - Massini, Annalisa A1 - Sinisi, Stefano A1 - Tronci, Enrico A1 - Davi, Francesco A1 - Dierkes, Thomas A1 - Ehrig, Rainald A1 - Röblitz, Susanna A1 - Leeners, Brigitte A1 - Krüger, Tillmann H. C. A1 - Egli, Marcel A1 - Ille, Fabian T1 - Patient-Specific Models from Inter-Patient Biological Models and Clinical Records T2 - Proceedings of the 14th Conference on Formal Methods in Computer-Aided Design (FMCAD 2014) Y1 - 2014 SP - 207 EP - 214 ER - TY - JOUR A1 - Plöntzke, Julia A1 - Berg, Mascha A1 - Ehrig, Rainald A1 - Leonhard-Marek, Sabine A1 - Müller, Kerstin-Elisabeth A1 - Röblitz, Susanna T1 - Model Based Exploration of Hypokalemia in Dairy Cows JF - Scientific Reports N2 - Hypokalemia, characterized by too low serum potassium levels, is a severe mineral disorder which can be life threatening. It is increasingly diagnosed in veterinarian healthcare and a topic of ongoing research. In this paper, we explore the different originating conditions of hypokalemia: reduced potassium intake, increased excretion, acid-base disturbances, or increased insulin, by using a dynamic mathematical model for potassium balance in non-lactating and lactating cows. Simulations are compared with literature. The results give insights into the network dynamics and point to scenarios on which experimental effort should be focused. Application of mathematical models can assist in experimental planning as well as the reduction, refinement and replacement of animal experiments. Y1 - 2022 U6 - https://doi.org/10.1038/s41598-022-22596-0 VL - 12, 19781 ER - TY - CHAP A1 - Kratzenstein, Stefan A1 - Heller, Markus O. A1 - Ehrig, Rainald A1 - Duda, Georg A1 - Taylor, William R. T1 - The Hip Joint Centre can be determined to within 3 mm T2 - 17th Congress of the European Society of Biomechanics Y1 - 2010 CY - Edinburgh ER - TY - JOUR A1 - Taylor, William R. A1 - Pöpplau, Berry M. A1 - König, Christian A1 - Ehrig, Rainald A1 - Zachow, Stefan A1 - Duda, Georg A1 - Heller, Markus O. T1 - The medial-lateral force distribution in the ovine stifle joint during walking JF - Journal of Orthopaedic Research Y1 - 2011 U6 - https://doi.org/10.1002/jor.21254 VL - 29 IS - 4 SP - 567 EP - 571 ER - TY - CHAP A1 - Taylor, William R. A1 - Fröhlich, Annika A1 - Buttgereit, Frank A1 - Ehrig, Rainald A1 - Witaschek, Tom A1 - Duda, Georg ED - Kersting, Uwe ED - Morlock, Michael ED - Jirova-Enzmann, Daniela ED - Dremstrup, Kim T1 - Metacarpophalangeal joint stiffness is reduced in patients affected by rheumatoid arthritis after glucocorticoid medication T2 - Proceedings of the ESM-2012, Aalborg Y1 - 2012 SP - 39 PB - Department of Health Science and Technology, Aalborg University ER - TY - JOUR A1 - Heller, Markus O. A1 - Kratzenstein, Stefan A1 - Ehrig, Rainald A1 - Wassilew, Georgi A1 - Duda, Georg A1 - Taylor, William R. T1 - The weighted optimal common shape technique improves identification of the hip joint centre of rotation in vivo JF - Journal of Orthopedic Research Y1 - 2011 VL - 29 SP - 1470 EP - 5 ER - TY - JOUR A1 - Ehrig, Rainald A1 - Taylor, William R. A1 - Duda, Georg A1 - Heller, Markus O. T1 - A Survey for Formal Methods for Determining Functional Joint Axes JF - Journal of Biomechanics Y1 - 2007 SP - 2150 EP - 2157 ER - TY - CHAP A1 - Kratzenstein, Stefan A1 - Heller, Markus O. A1 - Ehrig, Rainald A1 - Wassilew, Georgi A1 - Duda, Georg A1 - Taylor, William R. T1 - A new approach for optimally reducing skin marker artifact allows determination of the hip joint center within 3mm T2 - Transactions Vol. 35, 2010 Annual Meeting of the Orthopedic Society Y1 - 2010 CY - New Orleans ER - TY - CHAP A1 - Kornaropoulos, Evgenios I. A1 - Taylor, William R. A1 - Duda, Georg A1 - Ehrig, Rainald A1 - Matziolis, Georg A1 - Müller, Michael A1 - Wassilew, Georgi A1 - Asbach, Patrick A1 - Perka, Carsten A1 - Heller, Markus O. T1 - An imageless method to quantify the mechanical femoral-tibial angle based on the functional determination of joint centers and axes T2 - Annual meeting of the ESMAC 2009 Y1 - 2009 CY - London ER - TY - JOUR A1 - Kornaropoulos, Evgenios I. A1 - Taylor, William R. A1 - Duda, Georg A1 - Ehrig, Rainald A1 - Matziolis, Georg A1 - Müller, Michael A1 - Wassilew, Georgi A1 - Asbach, Patrick A1 - Perka, Carsten A1 - Heller, Markus O. T1 - Frontal plane alignment: An imageless method to predict the mechanical femoral–tibial angle (mFTA) based on functional determination of joint centres and axes JF - Gait & Posture Y1 - 2010 U6 - https://doi.org/10.1016/j.gaitpost.2009.10.006 VL - 31 IS - 2 SP - 204 EP - 208 ER - TY - JOUR A1 - Boeth, Heide A1 - Biesen, Robert A1 - Hollnagel, Jeremias A1 - Herrmann, Sandra A1 - Ehrig, Rainald A1 - Pelli, Lorenzo A1 - Taylor, William R. A1 - Duda, Georg A1 - Buttgereit, Frank T1 - Quantification of morning stiffness to assess disease activity and treatment effects in rheumatoid arthritis JF - Rheumatology N2 - Objectives The clinical parameter “morning stiffness” is widely used to assess the status of rheumatoid arthritis (RA), but its accurate quantitative assessment in a clinical setting has not yet been successful. This lack of individual quantification limits both personalized medication and efficacy evaluation in the treatment of RA. Methods We have developed a novel technology to assess passive resistance of the metacarpophalangeal (MCP) III joint (stiffness) and its Passive Range of Motion (PRoM). Within this pilot study, nineteen female postmenopausal RA patients and nine healthy controls were examined in the evening as well as in the morning of the following day. To verify the specificity of the biomechanical quantification, eleven patients with RA were assessed both prior to and ∼3 h after glucocorticoid therapy. Results While the healthy controls showed only minor changes between afternoon and morning, in RA patients mean±SD PRoM decreased significantly by 18 ± 22% and stiffness increased significantly by 20 ± 18% in the morning compared with the previous afternoon. We found a significant positive correlation between RA activity and biomechanical measures. Glucocorticoids significantly increased mean PRoM by 16 ± 11% and reduced mean stiffness by 23 ± 22%. Conclusion This technology allowed mechanical stiffness to be quantified in MCP joints, and has demonstrated high sensitivity in respect to disease status as well as medication effect in RA patients. Such non-invasive, low risk, and rapid assessment of biomechanical joint stiffness opens a novel avenue for judging therapy efficacy in patients with RA, and potentially also in other non-RA inflammatory joint diseases. Y1 - 2021 U6 - https://doi.org/10.1093/rheumatology/keab323 VL - 60 IS - 11 SP - 5282 EP - 5291 ER - TY - JOUR A1 - Alves, Sónia A1 - Ehrig, Rainald A1 - Raffalt, Peter C. A1 - Bender, Alwina A1 - Duda, Georg A1 - Agres, Alison N. T1 - Quantifying Asymmetry in Gait: A Weighted Universal Symmetry Index to Evaluate 3D Ground Reaction Forces JF - Frontiers in Bioengineering and Biotechnology N2 - Though gait asymmetry is used as a metric of functional recovery in clinical rehabilitation, there is no consensus on an ideal method for its evaluation. Various methods have been proposed but are limited in scope, as they can often use only positive signals or discrete values extracted from time-scale data as input. By defining five symmetry axioms, a framework for benchmarking existing methods was established and a new method was described here for the first time: the weighted universal symmetry index (wUSI), which overcomes limitations of other methods. Both existing methods and the wUSI were mathematically compared to each other and in respect to their ability to fulfill the proposed symmetry axioms. Eligible methods that fulfilled these axioms were then applied using both discrete and continuous approaches to ground reaction force (GRF) data collected from healthy gait, both with and without artificially induced asymmetry using a single instrumented elbow crutch. The wUSI with a continuous approach was the only symmetry method capable of determining GRF asymmetries in different walking conditions in all three planes of motion. When used with a continuous approach, the wUSI method was able to detect asymmetries while avoiding artificial inflation, a common problem reported in other methods. In conclusion, the wUSI is proposed as a universal method to quantify three-dimensional GRF asymmetries, which may also be expanded to other biomechanical signals. Y1 - 2020 ER - TY - CHAP A1 - Krämer, Martin A1 - Herrmann, Karl-Heinz A1 - Boeth, Heide A1 - Tycowicz, Christoph von A1 - König, Christian A1 - Zachow, Stefan A1 - Ehrig, Rainald A1 - Hege, Hans-Christian A1 - Duda, Georg A1 - Reichenbach, Jürgen T1 - Measuring 3D knee dynamics using center out radial ultra-short echo time trajectories with a low cost experimental setup T2 - ISMRM (International Society for Magnetic Resonance in Medicine), 23rd Annual Meeting 2015, Toronto, Canada Y1 - 2015 ER - TY - CHAP A1 - Boeth, Heide A1 - Duda, Georg A1 - Hinzmann, Daniel A1 - Taylor, William R. A1 - Ehrig, Rainald A1 - Witaschek, Tom A1 - Buttgereit, Frank T1 - Objektive Quantifizierung der Morgensteifigkeit als Parameter für rheumatoide Arthritis im Metacarpophalangealgelenk T2 - 9. Jahrestagung der Deutschen Gesellschaft für Biomechanik (DGfB), Bonn Y1 - 2015 ER - TY - JOUR A1 - Boeth, Heide A1 - Duda, Georg A1 - Hinzmann, Daniel A1 - Hermann, Sandra A1 - Taylor, William R. A1 - Ehrig, Rainald A1 - Witaschek, Tom A1 - Buttgereit, Frank T1 - A Novel Approach to Quantify Morning Stiffness in Patients with Rheumatoid Arthritis JF - Annual European Congress of Rheumatology, EULAR 2015, Rome Y1 - 2015 ER - TY - CHAP A1 - Kornaropoulos, Evgenios I. A1 - Taylor, William R. A1 - Duda, Georg A1 - Ehrig, Rainald A1 - Heller, Markus O. T1 - Frontal plane lower limb alignment using functionally determined joint centers and axes T2 - International Conference on Computational Bioengineering Y1 - 2009 ER -