@misc{AuerReinkerSuessetal., author = {Auer, Simon and Reinker, Lukas and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Comparing calculated and measured muscle activity of thigh muscles in dynamic motion.}, series = {27th Congress of the European Society of Biomechanics, 26 - 29 June 2022, Porto, Portugal}, journal = {27th Congress of the European Society of Biomechanics, 26 - 29 June 2022, Porto, Portugal}, pages = {640}, language = {en} } @misc{MelznerPfeiferSuessetal., author = {Melzner, Maximilian and Pfeifer, Christian and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Muskuloskeletal analysis of elbow stability for common injury patterns}, series = {27th Congress of the European Society of Biomechanics, 26 - 29 June 2022, Porto, Portugal}, journal = {27th Congress of the European Society of Biomechanics, 26 - 29 June 2022, Porto, Portugal}, pages = {654}, language = {en} } @misc{KoeglerIsmailRusavyetal., author = {K{\"o}gler, Michael and Ismail, Khaled M. and Rusavy, Zdenek and Kalis, Vladimir and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Influence of bed height and stance on accoucheurs lower back and glenohumeral load during simulated childbirth}, series = {31st meeting of Czech Urogynaecological Society, Prague, 2022}, journal = {31st meeting of Czech Urogynaecological Society, Prague, 2022}, language = {en} } @misc{PfingstenBorgettoTomlinetal., author = {Pfingsten, Andrea and Borgetto, Bernhard and Tomlin, George S. and Max, Susanne and Trickes, Claudia}, title = {The Research Pyramid. Establishing the value of evidence from multiple research approaches in a systematic review}, series = {World Physical Therapy Congress der World Confederation for Physical Therapy (WCPT), Amsterdam, 2011}, journal = {World Physical Therapy Congress der World Confederation for Physical Therapy (WCPT), Amsterdam, 2011}, abstract = {Goal: The Research Pyramid is a model that values and integrates external evidence from multiple research approaches: experimental and observational as well as quantitative and qualitative. It provides a basis to collect and synthesize research findings for answering questions that emerge in therapy practice and for subsequent decision making, based on research evidence.}, language = {en} } @misc{AltenbuchnerHaugMohretal., author = {Altenbuchner, Amelie and Haug, Sonja and Mohr, Christa and Scorna, Ulrike and Weber, Karsten}, title = {The impact of nurse advisors and online advice services on treatment adherence in multiple sclerosis (MS)}, series = {7th Joint European Committee for Treatment and Research in Multiple Sclerosis - Americas Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS-ACTRIMS), 25.-27.10.2017, Paris}, journal = {7th Joint European Committee for Treatment and Research in Multiple Sclerosis - Americas Committee for Treatment and Research in Multiple Sclerosis (ECTRIMS-ACTRIMS), 25.-27.10.2017, Paris}, language = {en} } @techreport{PfingstenBorgetto, author = {Pfingsten, Andrea and Borgetto, Bernhard}, title = {Efficacy and effectiveness of physical therapy in adults with rheumatoid arthritis}, edition = {Version: 14.05.2020}, abstract = {What is the efficacy of physical therapy in the treatment of rheumatoid arthritis? What is the effectiveness of physical therapy in the treatment of rheumatoid arthritis? Which differences do exist between efficacy and effectiveness of rheumatoid arthritis?}, language = {en} } @article{MuehlingSandriesserDendorferetal., author = {M{\"u}hling, Mischa and Sandriesser, Sabrina and Dendorfer, Sebastian and Augat, Peter}, title = {Assessment of implant internal stresses under physiological femoral loading: Translation to a simplified bending load model}, series = {Journal of Biomechanics}, journal = {Journal of Biomechanics}, number = {112229}, publisher = {Elsevier}, issn = {1873-2380}, doi = {10.1016/j.jbiomech.2024.112229}, pages = {17}, abstract = {The success of surgical treatment for fractures hinges on various factors, notably accurate surgical indication. The process of developing and certifying a new osteosynthesis device is a lengthy and costly process that requires multiple cycles of review and validation. Current methods, however, often rely on predecessor standards rather than physiological loads in specific anatomical locations. This study aimed to determine actual loads experienced by an osteosynthesis plate, exemplified by a standard locking plate for the femoral shaft, utilizing finite elements analysis (FEA) and to obtain the bending moments for implant development standard tests. A protocol was developed, involving the creation and validation of a fractured femur model fixed with a locking plate, mechanical testing, and FEA. The model's validation demonstrated exceptional accuracy in predicting deformations, and the FEA revealed peak stresses in the fracture bridging zone. Results of a parametric analysis indicate that larger fracture gaps significantly impact implant mechanical behavior, potentially compromising stability. This study underscores the critical need for realistic physiological conditions in implant evaluations, providing an innovative translational approach to identify internal loads and optimize implant designs. In conclusion, this research contributes to enhancing the understanding of implant performance under physiological conditions, promoting improved designs and evaluations in fracture treatments.}, language = {en} } @article{RusavyCechovaDendorferetal., author = {Rusavy, Zdenek and Cechova, Hana and Dendorfer, Sebastian and Kalis, Vladimir and Ismail, Khaled M.}, title = {Is the Finnish grip tight enough? A manometric study of two manual perineal protection techniques}, series = {Acta Obstetricia et Gynecologica Scandinavica}, journal = {Acta Obstetricia et Gynecologica Scandinavica}, edition = {Early view}, publisher = {Wiley}, doi = {10.1111/aogs.15033}, language = {en} } @article{MelznerSuessDendorfer, author = {Melzner, Maximilian and Suess, Franz and Dendorfer, Sebastian}, title = {The impact of anatomical uncertainties on the predictions of a musculoskeletal hand model - a sensitivity study}, series = {Computer Methods in Biomechanics and Biomedical Engineering}, volume = {25}, journal = {Computer Methods in Biomechanics and Biomedical Engineering}, number = {2}, publisher = {Taylor \& Francis}, issn = {1476-8259}, doi = {10.1080/10255842.2021.1940974}, pages = {156 -- 164}, abstract = {Outputs of musculoskeletal models should be considered probabilistic rather than deterministic as they are affected by inaccuracies and estimations associated with the development of the model. One of these uncertainties being critical for modeling arises from the determination of the muscles' line of action and the physiological cross-sectional area. Therefore, the aim of this study was to evaluate the outcome sensitivity of model predictions from a musculoskeletal hand model in comparison to the uncertainty of these input parameters. For this purpose, the kinematics and muscle activities of different hand movements (abduction of the fingers, abduction of the thumb, and flexion of the thumb) were recorded. One thousand simulations were calculated for each movement using the Latin hypercube sampling method with a corresponding variation of the muscle origin/insertion points and the cross-sectional area. Comparing the standard hand to simulations incorporating uncertainties of input parameters shows no major deviations in on- and off-set time point of muscle activities. About 60\% of simulations are located within a ± 30\% interval around the standard model concerning joint reaction forces. The comparison with the variation of the input data leads to the conclusion that the standard hand model is able to provide not over-scattered outcomes and, therefore, can be considered relatively stable. These results are of practical importance to the personalization of a musculoskeletal model with subject-specific bone geometries and hence changed muscle line of action.}, subject = {Biomechanik}, language = {en} } @article{MelznerEngelhardtSimonetal., author = {Melzner, Maximilian and Engelhardt, Lucas and Simon, Ulrich and Dendorfer, Sebastian}, title = {Electromyography-Based Validation of a Musculoskeletal Hand Model}, series = {Journal of Biomechanical Engineering}, volume = {144}, journal = {Journal of Biomechanical Engineering}, number = {2}, publisher = {American Society of Mechanical Engineers, ASME}, doi = {10.1115/1.4052115}, pages = {8}, abstract = {Regarding the prevention of injuries and rehabilitation of the human hand, musculoskeletal simulations using an inverse dynamics approach allow for insights of the muscle recruitment and thus acting forces on the hand. Currently, several hand models from various research groups are in use, which are mainly validated by the comparison of numerical and anatomical moment arms. In contrast to this validation and model-building technique by cadaver studies, the aim of this study is to further validate a recently published hand model [1] by analyzing numerically calculated muscle activities in comparison to experimentally measured electromyographical signals of the muscles. Therefore, the electromyographical signals of 10 hand muscles of five test subjects performing seven different hand movements were measured. The kinematics of these tasks were used as input for the hand model, and the numerical muscle activities were computed. To analyze the relationship between simulated and measured activities, the time difference of the muscle on- and off-set points was calculated, which resulted in a mean on- and off-set time difference of 0.58 s between the experimental data and the model. The largest differences were detected for movements that mainly addressed the wrist. One major issue comparing simulated and measured muscle activities of the hand is cross-talk. Nevertheless, the results show that the hand model fits the experiment quite accurately despite some limitations and is a further step toward patient-specific modeling of the upper extremity.}, subject = {Elektromyographie}, language = {en} } @inproceedings{GlemarecHoermannLaueretal., author = {Gl{\´e}marec, Yann and H{\"o}rmann, Amelie and Lauer, Norina and Buche, C{\´e}dric and Lugrin, Jean-Luc and Latoschik, Marc Erich}, title = {Towards Virtual Audience Simulation For Speech Therapy}, series = {Proceedings of the 23rd ACM International Conference on Intelligent Virtual Agents (IVA '23), W{\"u}rzburg, September 19 - 22, 2023}, booktitle = {Proceedings of the 23rd ACM International Conference on Intelligent Virtual Agents (IVA '23), W{\"u}rzburg, September 19 - 22, 2023}, publisher = {Association for Computing Machinery}, address = {New York}, isbn = {78-1-4503-9994-4}, doi = {10.1145/3570945.3607348}, pages = {1-3}, abstract = {The utilization of virtual reality (VR) technology has shown promise in various therapeutic applications, particularly in exposure therapy for reducing fear of certain situations objects or activities, e.g. fear of height, or negative evaluation of others in social situations. VR has been shown to yield positive outcomes in follow-up studies, and provides a safe and ecological therapeutic environment for therapists and their patients. This paper presents a collaborative effort to develop a VR speech therapy system which simulates a virtual audience for users to practice their public speaking skills. We describe a novel web-based graphica user interface that enables therapists to manage the therapy session using a simple timeline. Lastly, we present the results from a qualitative study with therapists and teachers with functional dysphonia, which highlight the potential of such an application to support and augment the therapists' work and the remaining challenges regarding the design of natural interactions, agent behaviours and scenario customisation for patients.}, subject = {Stimme}, language = {en} } @article{MennCorstenLaueretal., author = {Menn, Lara and Corsten, Sabine and Lauer, Norina and Wallace, Sarah J.}, title = {The effectiveness of biographical approaches in long-term care: a systematic review}, series = {Gerontologist}, volume = {60}, journal = {Gerontologist}, number = {4}, doi = {10.1093/geront/gnz074}, pages = {309 -- 328}, abstract = {Background and Objectives Older adults in long-term residential aged care experience loneliness and reduced quality of life (QoL). Biographical approaches use the recall of the past events to increase self-efficacy, promote acceptance, and improve QoL. The aim of the systematic review was to examine the effectiveness of biographical approaches in improving the QoL of older adults in long-term residential aged care. Research Design and Methods This systematic review was conducted in accordance with PRISMA guidelines, using databases Medline, CINAHL, and the Cochrane Library. A 2-phase search strategy was used to identify research literature relating to the use of biographical interventions. Narrative analysis was used to synthesize results. Results Twenty-one studies met inclusion criteria for this review, comprising both group and individual interventions. The findings were inconsistent. Subjective elements of QoL of older adults improved in a narrow majority of the studies. Of a total of 21 outcomes investigated in group interventions, 11 resulted in significant improvements in QoL. The 16 outcomes of the individual interventions resulted in 10 significant improvements. The most significant influence was observed in life satisfaction. Group reminiscence also had a particularly strong influence on self-esteem. Discussion and Implications Although benefits were observed, it remains unclear why some interventions led to improvements in subjective elements of QoL and others did not. Exploration of the participant perspective through qualitative data collection and more detailed description of interventions in future studies could lead to a better understanding of the treatment components that are related to improved outcomes for older adults.}, language = {en} } @misc{LauerCorsten, author = {Lauer, Norina and Corsten, Sabine}, title = {Supporting peer-led aphasia support groups with a specific training program: a first proof of concept}, series = {International Aphasia Rehabilitation Conference, London}, journal = {International Aphasia Rehabilitation Conference, London}, language = {en} } @article{LauerCorsten, author = {Lauer, Norina and Corsten, Sabine}, title = {Quality of life in leaders and members of peer-led aphasia support groups - preliminary results of a systematic approach}, series = {Aphasiology}, volume = {32}, journal = {Aphasiology}, number = {sup1: International Aphasia Rehabilitation Conference (IARC)}, publisher = {Taylor\&Francis}, doi = {10.1080/02687038.2018.1485839}, pages = {119 -- 121}, language = {en} } @inproceedings{BirkenmaierKrenkel, author = {Birkenmaier, Clemens and Krenkel, Lars}, title = {Convolutional Neural Networks for Approximation of Internal Non-Newtonian Multiphase Flow Fields}, series = {14th World Congress on Computational Mechanics (WCCM), ECCOMAS Congress 2020: 19-24 July 2020, Paris, France}, booktitle = {14th World Congress on Computational Mechanics (WCCM), ECCOMAS Congress 2020: 19-24 July 2020, Paris, France}, editor = {Chinesta, F. and Abgrall, R. and Allix, O. and Kalistke, M}, publisher = {CIMNE}, doi = {10.23967/wccm-eccomas.2020.107}, abstract = {Neural networks (NNs) as an alternative method for universal approximation of differential equations have proven to be computationally efficient and still sufficiently accurate compared to established methods such as the finite volume method (FVM). Additionally, analysing weights and biases can give insights into the underlying physical laws. FVM and NNs are both based upon spacial discretisation. Since a Cartesian and equidistant grid is a raster graphics, image-to-image regression techniques can be used to predict phase velocity fields as well as particle and pressure distributions from simple mass flow boundary conditions. The impact of convolution layer depth and number of channels of a ConvolutionDeconvolution Regression Network (CDRN), on prediction performance of internal non-Newtownian multiphase flows is investigated. Parametric training data with 2055 sets is computed using FVM. To capture significant non-Newtownian effects of a particle-laden fluid (e.g. blood) flowing through small and non-straight channels, an Euler-Euler multiphase approach is used. The FVM results are normalized and mapped onto an equidistant grid as supervised learning target. The investigated NNs consist of n= {3, 5, 7} corresponding encoding/decoding blocks and different skip connections. Regardless of the convolution depth (i.e. number of blocks), the deepest spacial down-sampling via strided convolution is adjusted to result in a 1 × 1 × f · 2nfeature map, with f = {8, 16, 32}. The prediction performance expressed is as channel-averaged normalized root mean squared error (NRMSE). With a NRMSE of < 2 · 10-3, the best preforming NN has f = 32 initial feature maps, a kernel size of k = 4, n = 5 blocks and dense skip connections. Average inference time from this NN takes < 7 · 10-3s. Worst accuracy at NRMSE of approx 9 · 10-3is achieved without any skips, at k = 2, f = 16 and n = 3, but deployment takes only < 2 · 10-3s Given an adequate training, the prediction accuracy improves with convolution depth, where more features have higher impact on deeper NNs. Due to skip connections and batch normalisation, training is similarly efficient, regardless of the depth. This is further improved by blocks with dense connections, but at the price of a drastically larger model. Depending on geometrical complexity, spacial resolution is critical, as it increases the number of learnables and memory requirements massively.}, language = {en} } @inproceedings{StelzerTauwaldVielsmeieretal., author = {Stelzer, Vera and Tauwald, Sandra Melina and Vielsmeier, Veronika and Cieplik, Fabian and Kandulski, Arne and Schneider-Brachert, Wulf and W{\"u}nsch, Olaf and R{\"u}tten, Markus and Krenkel, Lars}, title = {Generation and Distribution of Surgical Smoke During High Frequency Electrocauterization}, series = {New Results in Numerical and Experimental Fluid Mechanics XIV. STAB/DGLR Symposium 2022}, booktitle = {New Results in Numerical and Experimental Fluid Mechanics XIV. STAB/DGLR Symposium 2022}, editor = {Dillman, Andreas and Heller, Gerd and Kraemer, Ewald and Wagner, Claus and Weiss, Julien}, publisher = {Springer Nature Switzerland AG}, address = {Cham, Switzerland}, isbn = {978-3-031-40481-8}, doi = {10.1007/978-3-031-40482-5_53}, pages = {559 -- 568}, abstract = {Surgical Smoke is generated during the cauterization of tissue with high-frequency (HF) devices and consists of 95\% water vapor and 5\% cellular debris. When the coagulation tweezers, which are supplied with HF voltage by the HF device, touch tissue, the electric circuit is closed, and smoke is generated by the heat. In-vivo investigations are performed during tracheotomies where surgical smoke is produced during coagulation of tissue. Furthermore, in-vitro parametric studies to investigate the particle number and size distribution and the spatial distribution of surgical smoke with laser light sheet technique are conducted. With higher power of the HF device, the particles generated are larger in size and the total number of particles generated is also higher. Adding artificial saliva to the tissue shows even higher particle counts. The study by laser light sheet also confirms this. The resulting characteristic size distribution, which may include viruses and bacterial components, confirms considering the risk arising from surgical smoke. Furthermore, the experiments will provide the database for further numerical investigations.}, language = {en} } @misc{TauwaldQuadrioRuettenetal., author = {Tauwald, Sandra Melina and Quadrio, Maurizio and R{\"u}tten, Markus and Stemmer, Christian and Krenkel, Lars}, title = {High Spatial Resolution Tomo-PIV of the Nasopharynx Focussing on the Physiological Breathing Cycle}, series = {23. DGLR Fach-Symposium Str{\"o}mungen mit Abl{\"o}sung, 09./10. November 2022, Berlin, Deutschland}, journal = {23. DGLR Fach-Symposium Str{\"o}mungen mit Abl{\"o}sung, 09./10. November 2022, Berlin, Deutschland}, address = {G{\"o}ttingen}, organization = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt e.V. / Arbeitsgemeinschaft Str{\"o}mungen mit Abl{\"o}sung, AG STAB}, abstract = {Investigations of complex patient-specific flow in the nasopharynx requires high resolution numerical calculations validated by reliable experiments. When building the validation base and the benchmark of computational fluid dynamics, an experimental setup of the nasal airways was developed. The applied optical measurement technique of tomo-PIV supplies information on the governing flow field in three dimensions. This paper presents tomo-PIV measurements of the highly complex patient-specific geometry of the human trachea. A computertomographic scan of a person's head builds the basis of the experimental silicone model of the nasal airways. An optimised approach for precise refractive index matching avoids optical distortions even in highly complex non-free-of-sight 3D geometries. A linear-motor-driven pump generates breathing scenarios, based on measured breathing cycles. Adjusting of the CCD cameras' double-frame-rate PIV-Δt enables the detailed analysis of flow structures during different cycle phases. Merging regions of interest enables high spatial resolution acquisition of the flow field.}, language = {en} } @misc{StelzerTauwaldVielsmeieretal., author = {Stelzer, Vera and Tauwald, Sandra Melina and Vielsmeier, Veronika and Cieplik, Fabian and Kandulski, Arne and Schneider-Brachert, Wulf and Wuensch, Olaf and R{\"u}tten, Markus and Krenkel, Lars}, title = {Generation, Distribution, and Contagiousness of Surgical Smoke during Tracheotomies}, series = {23. DGLR Fach-Symposium Str{\"o}mungen mit Abl{\"o}sung, 09./10. November 2022, Berlin, Deutschland}, journal = {23. DGLR Fach-Symposium Str{\"o}mungen mit Abl{\"o}sung, 09./10. November 2022, Berlin, Deutschland}, address = {G{\"o}ttingen}, organization = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt e.V. / Arbeitsgemeinschaft Str{\"o}mungen mit Abl{\"o}sung, AG STAB}, abstract = {Surgical smoke has been a little discussed topic in the context of the current pandemic. Surgical smoke is generated during the cauterization of tissue with heat-generating devices and consists of 95\% water vapor and 5\% cellular debris in the form of particulate matter. In-vivo investigations are performed during tracheotomies where surgical smoke is produced during tissue electrocautery. Furthermore, in-vitro parametric studies to investigate the particle number and size distribution and the spatial distribution of surgical smoke with laser light sheet technique are conducted. The higher the power of the high-frequency-device the larger the particles in size and the higher the resulting particle counts. The images taken show the densest smoke at 40W with artificial saliva. The resulting characteristic size distribution, which may include viruses and bacterial components, confirms that the risk arising from surgical smoke should be considered. Furthermore, the experiments will provide the database for further numerical investigations.}, language = {en} } @article{StelzerKrenkel, author = {Stelzer, Vera and Krenkel, Lars}, title = {2D numerical investigations derived from a 3D dragonfly wing captured with a high-resolution micro-CT}, series = {Technology and health care : official journal of the European Society for Engineering and Medicine}, volume = {30}, journal = {Technology and health care : official journal of the European Society for Engineering and Medicine}, number = {1}, publisher = {IOS Press}, doi = {10.3233/THC-219010}, pages = {283 -- 289}, abstract = {BACKGROUND: Due to their corrugated profile, dragonfly wings have special aerodynamic characteristics during flying and gliding. OBJECTIVE: The aim of this study was to create a realistic 3D model of a dragonfly wing captured with a high-resolution micro-CT. To represent geometry changes in span and chord length and their aerodynamic effects, numerical investigations are carried out at different wing positions. METHODS: The forewing of a Camacinia gigantea was captured using a micro-CT. After the wing was adapted an error-free 3D model resulted. The wing was cut every 5 mm and 2D numerical analyses were conducted in Fluent® 2020 R2 (ANSYS, Inc., Canonsburg, PA, USA). RESULTS: The highest lift coefficient, as well as the highest lift-to-drag ratio, resulted at 0 mm and an angle of attack (AOA) of 5∘. At AOAs of 10∘ or 15∘, the flow around the wing stalled and a K{\´a}rm{\´a}n vortex street behind the wing becomes CONCLUSIONS: The velocity is higher on the upper side of the wing compared to the lower side. The pressure acts vice versa. Due to the recirculation zones that are formed in valleys of the corrugation pattern the wing resembles the form of an airfoil.}, language = {en} } @article{SchecklmannSchmausserKlingeretal., author = {Schecklmann, Martin and Schmausser, Maximilian and Klinger, Felix and Kreuzer, Peter M. and Krenkel, Lars and Langguth, Berthold}, title = {Resting motor threshold and magnetic field output of the figure-of-8 and the double-cone coil}, series = {scientific reports}, volume = {10}, journal = {scientific reports}, number = {1}, publisher = {Nature}, doi = {10.1038/s41598-020-58034-2}, abstract = {The use of the double-cone (DC) coil in transcranial magnetic stimulation (TMS) is promoted with the notion that the DC coil enables stimulation of deeper brain areas in contrast to conventional figure-of-8 (Fo8) coils. However, systematic comparisons of these two coil types with respect to the spatial distribution of the magnetic field output and also to the induced activity in superficial and deeper brain areas are limited. Resting motor thresholds of the left and right first dorsal interosseous (FDI) and tibialis anterior (TA) were determined with the DC and the Fo8 coil in 17 healthy subjects. Coils were orientated over the corresponding motor area in an angle of 45 degrees for the hand area with the handle pointing in posterior direction and in medio-lateral direction for the leg area. Physical measurements were done with an automatic gantry table using a Gaussmeter. Resting motor threshold was higher for the leg area in contrast to the hand area and for the Fo8 in contrast to the DC coil. Muscle by coil interaction was also significant providing higher differences between leg and hand area for the Fo8 (about 27\%) in contrast to the DC coil (about 15\%). Magnetic field strength was higher for the DC coil in contrast to the Fo8 coil. The DC coil produces a higher magnetic field with higher depth of penetration than the figure of eight coil.}, language = {en} }