@article{AfonsoPereiraWeberetal., author = {Afonso, Luis Claudio Sugi and Pereira, Clayton R. and Weber, Silke A. T. and Hook, Christian and Falc{\~a}o, Alexandre X. and Papa, Joao Paulo}, title = {Hierarchical learning using deep optimum-path forest}, series = {Journal of Visual Communication and Image Representation}, volume = {71}, journal = {Journal of Visual Communication and Image Representation}, number = {August}, publisher = {Elsevier}, doi = {10.1016/j.jvcir.2020.102823}, abstract = {Bag-of-Visual Words (BoVW) and deep learning techniques have been widely used in several domains, which include computer-assisted medical diagnoses. In this work, we are interested in developing tools for the automatic identification of Parkinson's disease using machine learning and the concept of BoVW. The proposed approach concerns a hierarchical-based learning technique to design visual dictionaries through the Deep Optimum-Path Forest classifier. The proposed method was evaluated in six datasets derived from data collected from individuals when performing handwriting exams. Experimental results showed the potential of the technique, with robust achievements.}, language = {en} } @incollection{AltenbuchnerWeber, author = {Altenbuchner, Amelie and Weber, Karsten}, title = {Geriatric trauma patients as research subjects in a technology-driven research project}, series = {Aging between Participation and Simulation}, booktitle = {Aging between Participation and Simulation}, editor = {Haltaufderheide, Joschka and Hovemann, Johanna and Vollmann, Jochen}, publisher = {De Gruyter}, address = {Berlin u.a.}, isbn = {9783110677485}, doi = {10.1515/9783110677485-006}, pages = {87 -- 104}, abstract = {This article highlights methodological and ethical challenges in research with adults of older and oldest age, by presenting field experiences of the current research project "Motion Monitoring of Geriatric Trauma Patients - Explorative Study on the Rehabilitation Process after Hip Fracture Using Sensor-based Data". Depiction of the survey situation, with regard to the subjects in particular, can serve as practical examples for designing future research projects. The group of older adults is a rather large and growing group for which research is required, especially concerning their heterogeneity, their individual autonomy and quality of life. It is assumed, that research designs of studies on the target group must be specifically adjusted, in particular when considering the attribution of vulnerability of the group members. At the same time, it is not clear yet what exact specifics of the subjects and target group must be considered in research designs, as surprisingly little is known about the target group as subjects and corresponding theories have been insufficiently tested. The exploratory long-term design of the research project presented in the second section of this chapter has a positive evaluation of an ethics committee. Still ethical challenges occurred in the field situation, that are illustrated in the third section of this chapter, by providing information on the patients, their role as research subjects, how they were recruited, how an informed consensus was reached, and in some cases how participation was rejected or abandoned. After a summary, the end of the paper is marked by recommendations on how to design future research projects. Cumulatively it must always be expected that interaction between researchers and research subjects of this target group can become very intensive, what requires to follow clearly defined procedures and at the same time to be prepared to act flexibly.}, language = {en} } @inproceedings{AuerKubowitschKrutschetal., author = {Auer, Simon and Kubowitsch, Simone and Krutsch, Werner and Renkawitz, Tobias and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Effect of mental demand on knee forces in professional youth soccer players}, series = {ISBS Proceedings Archive}, volume = {38}, booktitle = {ISBS Proceedings Archive}, number = {1, Art. 28}, abstract = {Soccer is one of the most popular sports all around the world. It is an injurious type of sport with a focus on lower extremities and high psychological pressure during matches. The stressor is linked with injuries and an increased musculoskeletal loading. This study investigates the influence of cognitive stress on the load profile of the knee joint. Twelve professional youth soccer players performed highly dynamic runs with and without additional cognitive stress. The runs were analysed with a musculoskeletal simulation software. The data analysis shows no difference in knee joint reaction loading under additional mental stress compared to the baseline. Yet running times are significantly lower in the baseline. While there is no increase in the joint loads, the running times indicate an altered movement behaviour when the subjects are exposed to additional mental demand.}, subject = {Kniegelenk}, language = {en} } @article{AuerKurbowitschSuessetal., author = {Auer, Simon and Kurbowitsch, Simone and S{\"u}ß, Franz and Renkawitz, Tobias and Krutsch, Werner and Dendorfer, Sebastian}, title = {Mental stress reduces performance and changes musculoskeletal loading in football-related movements}, series = {Science and Medicine in Football}, volume = {5}, journal = {Science and Medicine in Football}, number = {4}, publisher = {Taylor \& Francis}, doi = {10.1080/24733938.2020.1860253}, pages = {323 -- 329}, abstract = {Purpose: Football players have a high risk of leg muscle injuries, especially when exposed to mental stress. Hence, this study investigated the musculoskeletal response of elite youth football players during highly dynamic movements under stress. The hypothesis is that mental stress reduces performance and changes the muscular forces exerted. Materials \& methods: Twelve elite youth football players were subjected to mental stress while performing sports-specific change-of-direction movements. A modified version of the d2 attention test was used as stressor. The kinetics are computed using inverse dynamics. Running times and exerted forces of injury-prone muscles were analysed. Results: The stressor runs were rated more mentally demanding by the players (p = 0.006, rs = 0.37) with unchanged physical demand (p = 0.777, rs = 0.45). This resulted in 10\% longer running times under stress (p < 0.001, d = -1.62). The musculoskeletal analysis revealed higher peak muscle forces under mental stress for some players but not for others. Discussion: The study shows that motion capture combined with musculoskeletal computation is suitable to analyse the effects of stress on athletes in highly dynamic movements. For the first time in football medicine, our data quantifies an association between mental stress with reduced football players' performance and changes in muscle force.}, language = {en} } @article{AurbachSpickaSuessetal., author = {Aurbach, Maximilian and Spicka, Jan and S{\"u}ß, Franz and Dendorfer, Sebastian}, title = {Evaluation of musculoskeletal modelling parameters of the shoulder complex during humeral abduction above 90°}, series = {Journal of Biomechanics}, volume = {106}, journal = {Journal of Biomechanics}, number = {June}, publisher = {Elsevier}, doi = {10.1016/j.jbiomech.2020.109817}, abstract = {Based on electromyographic data and force measurements within the shoulder joint, there is an indication that muscle and resulting joint reaction forces keep increasing over an abduction angle of 90°. In inverse dynamics models, no single parameter could be attributed to simulate this force behaviour accordingly. The aim of this work is to implement kinematic, kinetic and muscle model modifications to an existing model of the shoulder (AnyBody™) and assess their single and combined effects during abduction up to 140° humeral elevation. The kinematics and the EMG activity of 10 test subjects were measured during humeral abduction. Six modifications were implemented in the model: alternative wrapping of the virtual deltoid muscle elements, utilization of a three element Hill model, strength scaling, motion capture driven clavicle elevation/protraction, translation of the GH joint in dependency of the acting forces and an alteration of the scapula/clavicle rhythm. From the six modifications, 16 different combinations were considered. Parameter combinations with the Hill model changed the resultant GH joint reaction force and led to an increase in force during abduction of the humerus above 90°. Under the premise of muscle activities and forces within the GH joint rising after 90° of humeral abduction, we propose that the Hill type muscle model is a crucial parameter for accurately modelling the shoulder. Furthermore, the outcome of this study indicates that the Hill model induces the co-contraction of the muscles of the shoulder without the need of an additional stability criterion for an inverse dynamics approach.}, subject = {Schultergelenk}, language = {en} } @article{AurbachŠpičkaSuessetal., author = {Aurbach, Maximilian and Špička, Jan and S{\"u}ß, Franz and Vychytil, J. and Havelkov{\´a}, Leonard and Ryba, T. and Dendorfer, Sebastian}, title = {Torus obstacle method as a wrapping approach of the deltoid muscle group for humeral abduction in musculoskeletal simulation}, series = {Journal of Biomechanics}, volume = {109}, journal = {Journal of Biomechanics}, number = {August}, publisher = {Elsevier}, doi = {10.1016/j.jbiomech.2020.109864}, abstract = {Musculoskeletal models of the shoulder complex are valuable research aids to investigate tears of the supraspinatus and the resulting mechanical impact during abduction of the humerus. One of the major contributors to this motion is the deltoid muscle group and for this, an accurate modeling of the lines of action is indispensable. The aim of this work was to utilize a torus obstacle wrapping approach for the deltoids of an existing shoulder model and assess the feasibility of the approach during humeral abduction. The shoulder model from the AnyBody™ modeling system was used as a platform. The size of the tori is based on a magnetic resonance imaging (MRI) approach and several kinematic couplings are implemented to determine the trajectories of the tori during abduction. To assess the model behavior, the moment arms of the virtual muscle elements and the resultant glenohumeral joint reaction force (GHJF) were compared with reference data from the literature during abduction of the humerus in the range 20°-120°. The root mean square error for the anterior, lateral and posterior part between the simulated muscle elements and reference data from the literature was 3.9, 1.7 and 5.8 mm, respectively. The largest deviation occurred on the outer elements of the muscle groups, with 12.6, 10.4 and 20.5 mm, respectively. During abduction, there is no overlapping of the muscle elements and these are in continuous contact with the torus obstacles, thus enabling a continuous force transmission. This results in a rising trend of the resultant GHJF. The torus obstacle approach as a wrapping method for the deltoid muscles provides a guided muscle pathing by simultaneously approximating the curvature of the deltoid muscle. The results from the comparison of the simulated moment arms and the resultant GHJF are in accordance with those in the literature in the range 20°-120° of abduction. Although this study shows the strength of the torus obstacle as a wrapping approach, the method of fitting the tori according to MRI data was not suitable. A cadaver study is recommended to better validate and mathematically describe the torus approach.}, language = {en} } @article{BirkenmaierDorniaLehleetal., author = {Birkenmaier, Clemens and Dornia, Christian and Lehle, Karla and M{\"u}ller, Thomas and Gruber, Michael Andreas and Philipp, Alois and Krenkel, Lars}, title = {Analysis of Thrombotic Deposits in Extracorporeal Membrane Oxygenators by High-resolution Microcomputed Tomography: A Feasibility Study}, series = {ASAIO Journal / American Society for Artificial Internal Organs}, volume = {66}, journal = {ASAIO Journal / American Society for Artificial Internal Organs}, number = {8}, publisher = {Lippincott Williams \& Wilkins}, issn = {1538-943X}, doi = {10.1097/MAT.0000000000001089}, pages = {922 -- 928}, abstract = {Coagulative disorders, especially clotting during extracorporeal membrane oxygenation, are frequent complications. Direct visualization and analysis of deposits in membrane oxygenators using computed tomography (CT) may provide an insight into the underlying mechanisms causing thrombotic events. However, the already established multidetector CT1 (MDCT) method shows major limitations. Here, we demonstrate the feasibility of applying industrial micro-CT (μCT) to circumvent these restrictions. Three clinically used membrane oxygenators were investigated applying both MDCT and μCT. The scans were analyzed in terms of clot volume and local clot distribution. As validation, the clot volume was also determined from the fluid volume, which could be filled into the respective used oxygenator compared to a new device. In addition, cross-sectional CT images were compared with crosscut oxygenators. Based on the μCT findings, a morphological measure (sphericity) for assessing clot structures in membrane oxygenators is introduced. Furthermore, by comparing MDCT and μCT results, an augmentation of the MDCT method is proposed, which allows for improved clot volume determination in a clinical setting.}, language = {en} } @article{BrabenecPoborskySassmannshausen, author = {Brabenec, Tomas and Poborsky, Frantisek and Saßmannshausen, Sean Patrick}, title = {The Difference between Preferred \& Common Stocks in Europe from the Market Perspective}, series = {Journal of Competitiveness}, volume = {12}, journal = {Journal of Competitiveness}, number = {3}, publisher = {Tomas Bata University in Zl{\´i}n}, doi = {10.7441/joc.2020.03.04}, pages = {64 -- 81}, abstract = {Companies listed on the stock market must devote a great deal of attention to their market position. They must increase their competitive advantage in the undeniably key process of the issuance of stocks. As the issuance of preferred stocks has increased after the last crisis and in the current period of low interest rates in Europe, they are becoming more favoured investment instruments, we decided to analyse the real properties of preferred stocks in Europe in order to increase the efficiency of joint-stock companies. Using a dataset comprising all companies having both common and preferred stocks issued and traded on European markets between 2009- 2016, we determined the relationship of risk (measured by beta coefficients) and price volatility among common and preferred stocks and bonds in Europe. Our findings show beta coefficients of preferred stocks as systematically lower than beta coefficients of common stocks. Considering a difference of up to 10\% as negligible, however, preferred stocks showed a similar or higher beta coefficient than corresponding common stocks of the same company in 53\% of cases, whereas for 33\% of cases, the difference is only ±10\%. Coefficients of variation in prices showed a similar relationship, with only a negligible portion of preferred stocks bearing fixed (stable) dividends. This result implies that currently traded preferred stocks in Europe in fact do not possess such characteristics they are typically said to have, and in many cases they incur as comparable a risk as do common stocks. This essential information should help to increase the efficiency and competitiveness of joint-stock companies.}, language = {en} } @inproceedings{ChangLinLeeetal., author = {Chang, Ching-Sheng and Lin, Jin-Fa and Lee, Ming-Ching and Palm, Christoph}, title = {Semantic Lung Segmentation Using Convolutional Neural Networks}, series = {Bildverarbeitung f{\"u}r die Medizin 2020. Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 15. bis 17. M{\"a}rz 2020 in Berlin}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2020. Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 15. bis 17. M{\"a}rz 2020 in Berlin}, editor = {Tolxdorff, Thomas and Deserno, Thomas M. and Handels, Heinz and Maier, Andreas and Maier-Hein, Klaus H. and Palm, Christoph}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-29266-9}, doi = {10.1007/978-3-658-29267-6_17}, pages = {75 -- 80}, abstract = {Chest X-Ray (CXR) images as part of a non-invasive diagnosis method are commonly used in today's medical workflow. In traditional methods, physicians usually use their experience to interpret CXR images, however, there is a large interobserver variance. Computer vision may be used as a standard for assisted diagnosis. In this study, we applied an encoder-decoder neural network architecture for automatic lung region detection. We compared a three-class approach (left lung, right lung, background) and a two-class approach (lung, background). The differentiation of left and right lungs as direct result of a semantic segmentation on basis of neural nets rather than post-processing a lung-background segmentation is done here for the first time. Our evaluation was done on the NIH Chest X-ray dataset, from which 1736 images were extracted and manually annotated. We achieved 94:9\% mIoU and 92\% mIoU as segmentation quality measures for the two-class-model and the three-class-model, respectively. This result is very promising for the segmentation of lung regions having the simultaneous classification of left and right lung in mind.}, subject = {Neuronales Netz}, language = {en} } @article{CorstenLauer, author = {Corsten, Sabine and Lauer, Norina}, title = {Biography work in long-term residential aged care with tablet support to improve the quality of life and communication - study protocol for app development and evaluation}, series = {International Journal of Health Professions}, volume = {7}, journal = {International Journal of Health Professions}, number = {1}, doi = {10.2478/ijhp-2020-0002}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-8446}, pages = {13 -- 23}, abstract = {Hintergrund {\"A}ltere Menschen in Pflegeeinrichtungen haben ein hohes Risiko, an Depressionen zu erkranken. Die Auswirkungen fr{\"u}her Interventionen wie Biografiearbeit auf die Lebensqualit{\"a}t {\"a}lterer, institutionalisierter Personen sind unerforscht. Ziel Entwicklung und Evaluation einer tablet-gest{\"u}tzten Intervention zur Biografiearbeit in der station{\"a}ren Langzeitpflege zur Steigerung der Lebensqualit{\"a}t {\"a}lterer Menschen. Design Die Studie wird in einem randomisierten Pre-Test-Post-Test-Kontrollgruppen-Design mit Follow-up-Testung im Gruppen- und Einzel-Setting durchgef{\"u}hrt. Die Teilnehmenden werden randomisiert der experimentellen Intervention (Tablet-gest{\"u}tzte biografische Arbeit) oder der Kontrollintervention (geplant Tablet-gest{\"u}tztes Spiel), die jeweils von {\"a}lteren, ehrenamtlich Helfenden unterst{\"u}tzt werden, zugewiesen. Insgesamt werden 80 Bewohner/-innen und 16 Ehrenamtliche rekrutiert. Prim{\"a}rer Outcome ist die Lebensqualit{\"a}t der Bewohner/-innen und der ehrenamtlich Helfenden, gemessen mit dem World Health Organization Quality of Life Assessment for older adults. Sekund{\"a}rer Outcome sind Selbstwertgef{\"u}hl und Lebenszufriedenheit. Dar{\"u}ber hinaus werden Kommunikationsf{\"a}higkeit und die funktionale Unabh{\"a}ngigkeit der Bewohner/-innen untersucht. Methode In der ersten Projektphase wird eine App im Sinne eines benutzerzentrierten, agilen Entwicklungsprozesses konzipiert, die multimodal lebensgeschichtliche Themen aufbereitet und mit Schl{\"u}sselfragen verkn{\"u}pft. F{\"u}r {\"a}ltere Ehrenamtliche, die den Einsatz der App in den Institutionen begleiten, wird ein Workshop entwickelt. In der zweiten Phase wird die von der App angeregte biografische Arbeit im Gruppen- und Einzel-Setting durchgef{\"u}hrt. Diskussion Dies ist das erste bekannte Programm, das auf {\"a}ltere Menschen in Pflegeeinrichtungen und {\"a}ltere Ehrenamtliche zugeschnitten ist und darauf abzielt, Depressionen durch digital unterst{\"u}tzte biografische Arbeit vorzubeugen.}, language = {en} } @article{deCamposSilvaBaimaRibeirodeBarrosetal., author = {de Campos Silva, Elen Farinelli and Baima, Julio Pinheiro and Ribeiro de Barros, Jaqueline and Tanni, Suzana and Schreck, Thomas and Saad-Hossne, Rogerio and Sassaki, Ligia Yukie}, title = {Risk factors for ulcerative colitis-associated colorectal cancer A retrospective cohort study}, series = {Medicine}, volume = {99}, journal = {Medicine}, number = {32}, publisher = {Lippincott}, doi = {10.1097/MD.0000000000021686}, pages = {1 -- 6}, abstract = {Inflammatory bowel disease is associated with an increased risk of colorectal cancer. The study aims to identify the risk factors for ulcerative colitis-colorectal cancer and to perform a survival curve analysis of the outcome. This retrospective cohort study included 254 patients from March 2016 to October 2017. Age, age at diagnosis, follow-up time, smoking status, and family history of colorectal cancer were analyzed as risk factors for colorectal cancer. The mean patient age was 46.6 +/- 16.9 years; 5.5\% of the patients were smokers and 49.6\% had pancolitis. Six patients (2.36\%) had colorectal cancer, which was associated with age at diagnosis (odds/hazard ratio 1.059 [95\% confidence interval: 1.001-1.121];P = .04), family history of colorectal cancer (12.992 [1.611-104.7];P = .02), and follow-up time (0.665 [0.513-0.864];P = .002). Active smoking was the main identified risk factor, after both logistic (8.477 [1.350-53.232];P = .02) and Cox proportional-hazards (32.484 [2.465-428.1];P = .008) regression analysis. The risk of colorectal cancer was 3.17\% at 10 years and 4.26\% at 20 years of follow-up. Active smoking and family history were identified as risk factors for colorectal cancer. These findings should aid the early identification of patients who require vigorous surveillance, and prevent exposure to risk factors.}, language = {en} } @article{DePieriAtzoriFergusonetal., author = {De Pieri, Enrico and Atzori, Federica and Ferguson, Stephen J. and Dendorfer, Sebastian and Leunig, Michael and Aepli, Martin}, title = {Contact force path in total hip arthroplasty: effect of cup medialisation in a whole-body simulation}, series = {HIP International}, volume = {31}, journal = {HIP International}, number = {5}, publisher = {Sage}, doi = {10.1177/1120700020917321}, pages = {624 -- 631}, abstract = {Background: Cup medialisation down to the true acetabular floor in total hip arthroplasty with a compensatory femoral offset increase seems to be mechanically advantageous for the abductor muscles due to the relocation of the lever arms (body weight lever arm decreased, abductor lever arm increased). However, limited information is currently available about the effects of this reconstruction type at the head cup interface, compared to an anatomical reconstruction that maintains the natural lever arms. Through a whole-body simulation analysis, we compared medialised versus anatomical reconstruction in THA to analyse the effects on: (1) contact force magnitude at the head cup interface; (2) contact force path in the cup; and (3) abductor activity. Methods: Musculoskeletal simulations were performed to calculate the above-mentioned parameters using inverse dynamics analysis. The differences between the virtually implanted THAs were calculated to compare the medialised versus anatomical reconstruction. Results: Cup medialisation with compensatory femoral offset increase led to: (1) a reduction in contact force magnitude at the head cup interface up to 6.6\%; (2) a similar contact force path in the cup in terms of sliding distance and aspect ratio; and (3) a reduction in abductor activity up to 17.2\% (gluteus medius). Conclusions: In our opinion, these potential biomechanical gains do not generally justify a fully medialised reconstruction, especially in younger patients that are more likely to undergo revision surgery in their lifetime. Cup medialisation should be performed until sufficient press fit and bony coverage of a properly sized and oriented cup can be achieved.}, subject = {H{\"u}ftgelenkprothese}, language = {en} } @article{EbigboMendelProbstetal., author = {Ebigbo, Alanna and Mendel, Robert and Probst, Andreas and Manzeneder, Johannes and Prinz, Friederike and Souza Jr., Luis Antonio de and Papa, Jo{\~a}o Paulo and Palm, Christoph and Messmann, Helmut}, title = {Real-time use of artificial intelligence in the evaluation of cancer in Barrett's oesophagus}, series = {Gut}, volume = {69}, journal = {Gut}, number = {4}, publisher = {BMJ}, address = {London}, doi = {10.1136/gutjnl-2019-319460}, pages = {615 -- 616}, abstract = {Based on previous work by our group with manual annotation of visible Barrett oesophagus (BE) cancer images, a real-time deep learning artificial intelligence (AI) system was developed. While an expert endoscopist conducts the endoscopic assessment of BE, our AI system captures random images from the real-time camera livestream and provides a global prediction (classification), as well as a dense prediction (segmentation) differentiating accurately between normal BE and early oesophageal adenocarcinoma (EAC). The AI system showed an accuracy of 89.9\% on 14 cases with neoplastic BE.}, subject = {Speiser{\"o}hrenkrankheit}, language = {en} } @misc{EbigboMendelTziatziosetal., author = {Ebigbo, Alanna and Mendel, Robert and Tziatzios, Georgios and Probst, Andreas and Palm, Christoph and Messmann, Helmut}, title = {Real-Time Diagnosis of an Early Barrett's Carcinoma using Artificial Intelligence (AI) - Video Case Demonstration}, series = {Endoscopy}, volume = {52}, journal = {Endoscopy}, number = {S 01}, publisher = {Thieme}, doi = {10.1055/s-0040-1704075}, pages = {S23}, abstract = {Introduction We present a clinical case showing the real-time detection, characterization and delineation of an early Barrett's cancer using AI. Patients and methods A 70-year old patient with a long-segment Barrett's esophagus (C5M7) was assessed with an AI algorithm. Results The AI system detected a 10 mm focal lesion and AI characterization predicted cancer with a probability of >90\%. After ESD resection, histopathology showed mucosal adenocarcinoma (T1a (m), R0) confirming AI diagnosis. Conclusion We demonstrate the real-time AI detection, characterization and delineation of a small and early mucosal Barrett's cancer.}, subject = {Speiser{\"o}hrenkrebs}, language = {en} } @article{GeithEckmannHaspingeretal., author = {Geith, Markus A. and Eckmann, Jakob D. and Haspinger, Daniel Ch. and Agrafiotis, Emmanouil and Maier, Dominik and Szabo, Patrick and Sommer, Gerhard and Schratzenstaller, Thomas and Holzapfel, Gerhard A.}, title = {Experimental and mathematical characterization of coronary polyamide-12 balloon catheter membranes}, series = {PLoS One}, volume = {15}, journal = {PLoS One}, number = {6}, publisher = {PLOS}, doi = {10.1371/journal.pone.0234340}, pages = {1 -- 22}, abstract = {The experimental quantification and modeling of the multiaxial mechanical response of polymer membranes of coronary balloon catheters have not yet been carried out. Due to the lack of insights, it is not shown whether isotropic material models can describe the material response of balloon catheter membranes expanded with nominal or higher, supra-nominal pressures. Therefore, for the first time, specimens of commercial polyamide-12 balloon catheters membranes were investigated during uniaxial and biaxial loading scenarios. Furthermore, the influence of kinematic effects on the material response was observed by comparing results from quasi-static and dynamic biaxial extension tests. Novel clamping techniques are described, which allow to test even tiny specimens taken from the balloon membranes. The results of this study reveal the semi-compliant, nonlinear, and viscoelastic character of polyamide-12 balloon catheter membranes. Above nominal pressure, the membranes show a pronounced anisotropic mechanical behavior with a stiffer response in the circumferential direction. The anisotropic feature intensifies with an increasing strain-rate. A modified polynomial model was applied to represent the realistic mechanical response of the balloon catheter membranes during dynamic biaxial extension tests. This study also includes a compact set of constitutive model parameters for the use of the proposed model in future finite element analyses to perform more accurate simulations of expanding balloon catheters.}, language = {en} } @article{GeithNothdurfterHeimletal., author = {Geith, Markus A. and Nothdurfter, Laurenz and Heiml, Manuel and Agrafiotis, Emmanouil and Gruber, Markus and Sommer, Gerhard and Schratzenstaller, Thomas and Holzapfel, Gerhard A.}, title = {Quantifying stent-induced damage in coronary arteries by investigating mechanical and structural alterations}, series = {Acta Biomaterialia}, volume = {116}, journal = {Acta Biomaterialia}, number = {October}, publisher = {Elsevier}, doi = {10.1016/j.actbio.2020.08.016}, pages = {285 -- 301}, abstract = {Vascular damage develops with diverging severity during and after percutaneous coronary intervention with stent placement and is the prevailing stimulus for in-stent restenosis. Previous work has failed to link mechanical data obtained in a realistic in vivo or in vitro environment with data collected during imaging processes. We investigated whether specimens of porcine right coronary arteries soften when indented with a stent strut shaped structure, and if the softening results from damage mechanisms inside the fibrillar collagen structure. To simulate the multiaxial loading scenario of a stented coronary artery, we developed the testing device 'LAESIO' that can measure differences in the stress-stretch behavior of the arterial wall before and after the indentation of a strut-like stamp. The testing protocol was optimized according to preliminary experiments, more specifically equilibrium and relaxation tests. After chemical fixation of the specimens and subsequent tissue clearing, we performed three-dimensional surface and second-harmonic generation scans on the deformed specimens. We analyzed and correlated the mechanical response with structural parameters of high-affected tissue located next to the stamp indentation and low-affected tissue beyond the injured area. The results reveal that damage mechanisms, like tissue compression as well as softening, fiber dispersion, and the lesion extent, are direction-dependent, and the severity of them is linked to the strut orientation, indentation pressure, and position. The findings highlight the need for further investigations by applying the proposed methods to human coronary arteries. Additional data and insights might help to incorporate the observed damage mechanisms into material models for finite element analyses to perform more accurate simulations of stent-implantations.}, language = {en} } @article{GrabitzFriedmannGeppetal., author = {Grabitz, Peter and Friedmann, Zoe and Gepp, Sophie and Hess, Leonard U. and Specht, Lisa and Struck, Maja and Tragert, Sophie Kira and Walther, Tobias and Klemperer, David}, title = {Quantity and quality of conflict of interest policies at German medical schools}, series = {BMJ open}, volume = {10}, journal = {BMJ open}, number = {9}, publisher = {BMJ Publishing Group}, doi = {10.1136/bmjopen-2020-039782}, pages = {1 -- 8}, abstract = {OBJECTIVES: To assess the quantity and evaluate the quality of policies and curricula focusing on conflicts of interests (COI) at medical schools across Germany. DESIGN: Cross-sectional study, survey of medical schools, standardised web search. SETTING: Medical schools, Germany. PARTICIPANTS: 38 German medical schools. - INTERVENTIONS: We collected relevant COI policies, including teaching activities, by conducting a search of the websites of all 38 German medical schools using standardised keywords for COI policies and teaching. Further, we surveyed all medical schools' dean's offices. Finally, we adapted a scoring system for results we obtained with 13 categories based on prior similar studies. MAIN OUTCOMES AND MEASURES: Presence or absence of COI-related policies, including teaching activities at medical school. The secondary outcome was the achieved score on a scale from 0 to 26, with high scores representing restrictive policies and sufficient teaching activities. RESULTS: We identified relevant policies for one medical school via the web search. The response rate of the deans' survey was 16 of 38 (42.1\%). In total, we identified COI-related policies for 2 of 38 (5.3\%) German medical schools, yet no policy was sufficient to address all COI-related categories that were assessed in this study. The maximum score achieved was 12 of 26. 36 (94.7\%) schools scored 0. No medical school reported curricular teaching on COI. CONCLUSIONS: Our results indicate a low level of action by medical schools to protect students from undue commercial influence. No participating dean was aware of any curriculum or instruction on COI at the respective school and only two schools had policies in place. The German Medical Students Association and international counterparts have called for a stronger focus on COI in the classroom. We conclude that for German medical schools, there is still a long way to go.}, language = {en} } @article{HartmannWeihererSchiltzetal., author = {Hartmann, Robin and Weiherer, Maximilian and Schiltz, Daniel and Seitz, Stephan and Lotter, Luisa and Anker, Alexandra and Palm, Christoph and Prantl, Lukas and Br{\´e}bant, Vanessa}, title = {A Novel Method of Outcome Assessment in Breast Reconstruction Surgery: Comparison of Autologous and Alloplastic Techniques Using Three-Dimensional Surface Imaging}, series = {Aesthetic Plastic Surgery}, volume = {44}, journal = {Aesthetic Plastic Surgery}, publisher = {Springer}, address = {Heidelberg}, doi = {10.1007/s00266-020-01749-4}, pages = {1980 -- 1987}, abstract = {Background Breast reconstruction is an important coping tool for patients undergoing a mastectomy. There are numerous surgical techniques in breast reconstruction surgery (BRS). Regardless of the technique used, creating a symmetric outcome is crucial for patients and plastic surgeons. Three-dimensional surface imaging enables surgeons and patients to assess the outcome's symmetry in BRS. To discriminate between autologous and alloplastic techniques, we analyzed both techniques using objective optical computerized symmetry analysis. Software was developed that enables clinicians to assess optical breast symmetry using three-dimensional surface imaging. Methods Twenty-seven patients who had undergone autologous (n = 12) or alloplastic (n = 15) BRS received three-dimensional surface imaging. Anthropomorphic data were collected digitally using semiautomatic measurements and automatic measurements. Automatic measurements were taken using the newly developed software. To quantify symmetry, a Symmetry Index is proposed. Results Statistical analysis revealed that there is no dif- ference in the outcome symmetry between the two groups (t test for independent samples; p = 0.48, two-tailed). Conclusion This study's findings provide a foundation for qualitative symmetry assessment in BRS using automatized digital anthropometry. In the present trial, no difference in the outcomes' optical symmetry was detected between autologous and alloplastic approaches.}, subject = {Mammoplastik}, language = {en} } @article{HuberSchlosserStenzeletal., author = {Huber, Michaela and Schlosser, Daniela and Stenzel, Susanne and Maier, Johannes and Pattappa, Girish and Kujat, Richard and Striegl, Birgit and Docheva, Denitsa}, title = {Quantitative Analysis of Surface Contouring with Pulsed Bipolar Radiofrequency on Thin Chondromalacic Cartilage}, series = {BioMed Research International}, journal = {BioMed Research International}, publisher = {HINDAWI}, doi = {10.1155/2020/1242086}, pages = {1 -- 8}, abstract = {The purpose of this study was to evaluate the quality of surface contouring of chondromalacic cartilage by bipolar radio frequency energy using different treatment patterns in an animal model, as well as examining the impact of the treatment onto chondrocyte viability by two different methods. Our experiments were conducted on 36 fresh osteochondral sections from the tibia plateau of slaughtered 6-month-old pigs, where the thickness of the cartilage is similar to that of human wrist cartilage. An area of 1 cm(2) was first treated with emery paper to simulate the chondromalacic cartilage. Then, the treatment with RFE followed in 6 different patterns. The osteochondral sections were assessed for cellular viability (live/dead assay, caspase (cell apoptosis marker) staining, and quantitative analysed images obtained by fluorescent microscopy). For a quantitative characterization of none or treated cartilage surfaces, various roughness parameters were measured using confocal laser scanning microscopy (Olympus LEXT OLS 4000 3D). To describe the roughness, the Root-Mean-Square parameter (Sq) was calculated. A smoothing effect of the cartilage surface was detectable upon each pattern of RFE treatment. The Sq for native cartilage was Sq=3.8 +/- 1.1 mu m. The best smoothing pattern was seen for two RFE passes and a 2-second pulsed mode (B2p2) with an Sq=27.3 +/- 4.9 mu m. However, with increased smoothing, an augmentation in chondrocyte death up to 95\% was detected. Using bipolar RFE treatment in arthroscopy for small joints like the wrist or MCP joints should be used with caution. In the case of chondroplasty, there is a high chance to destroy the joint cartilage.}, language = {en} } @inproceedings{JahnMottok, author = {Jahn, Sabrina and Mottok, J{\"u}rgen}, title = {Work in Progress: Towards an Academic Secure Software Engineering Curriculum for Engineers}, series = {2020 IEEE Global Engineering Education Conference (EDUCON): 27-30 April 2020, Porto, Portugal}, booktitle = {2020 IEEE Global Engineering Education Conference (EDUCON): 27-30 April 2020, Porto, Portugal}, doi = {10.1109/EDUCON45650.2020.9125210}, pages = {1713 -- 1717}, abstract = {In the age of the Internet of Things, it is becoming increasingly important to integrate knowledge about the development of secure systems (Secure Software Engineering) into academic teaching. However, teaching IT Security and Secure Software Engineering to non-computer scientists is rare. Therefore, we focus our research on the integration of IT Security into software engineering education of non-computer scientists, particularly electrical engineers, by means of inductive teaching- and learning-arrangements. After collecting students' preconceptions of IT Security and Secure Software Engineering in prior work, this paper now contributes with a first mapping of these preconceptions with corresponding learning content as well as suitable inductive teaching methods to be able to create new lecture and exercise units and improve academic learning and teaching in both areas.}, language = {en} } @inproceedings{KloppGoldVeerkampAbkeetal., author = {Klopp, Marco and Gold-Veerkamp, Carolin and Abke, J{\"o}rg and Borgeest, Kai and Reuter, Rebecca and Jahn, Sabrina and Mottok, J{\"u}rgen and Sedelmaier, Yvonne and Lehmann, Alexander and Landes, Dieter}, title = {Totally Different and yet so Alike: Three Concepts to Use Scrum in Higher Education}, series = {Proceedings of the 4th European Conference on Software Engineering Education (ECSEE '20): June 2020, Seeon/Bavaria, Germany}, booktitle = {Proceedings of the 4th European Conference on Software Engineering Education (ECSEE '20): June 2020, Seeon/Bavaria, Germany}, doi = {10.1145/3396802.3396817}, pages = {12 -- 21}, abstract = {Software process models are important in software projects in order to give the work of a project guidelines or a framework. However, teaching process models in higher education seems to be quite challenging. This has to do with the fact that undergraduates have no experience with projects in which process models are used. The theoretical mediation of process models is initially on a very abstract level. For this reason, we chose to combine two didactic approaches, namely problem-based learning and project work. Various traditional plan-driven process models have been expanded in courses in Software Engineering with agile process models. The Scrum Framework is the focus of consideration of this paper. Three Universities of Applied Sciences which cooperate in the EVELIN project focused on Scrum as a process model and integrated it into their teaching. Since the respective concepts of implementation differ, they should be presented and compared in this article to presents some practice approaches. The goal of this presentation of is a uniform evaluation in order to obtain insights from different perspectives. This comparison can draw conclusions for possible necessary improvements of the respective concepts.}, language = {en} } @inproceedings{KoenigGuertlerŻarnowskaetal., author = {Koenig, Eric and Guertler, Katherine and Żarnowska, Dorota and Horbačauskienė, Jolita}, title = {Developing English language competence for global engineers}, series = {2020 IEEE Global Engineering Education Conference (EDUCON): 27-30 April 2020, Porto, Portugal}, booktitle = {2020 IEEE Global Engineering Education Conference (EDUCON): 27-30 April 2020, Porto, Portugal}, doi = {10.1109/EDUCON45650.2020.9125208}, pages = {242 -- 249}, abstract = {English language skills are essential to professional communication in international engineering environments. Given the concomitant degree of specialization, university-level coursework in English for Specific Purposes is an essential component of engineering student preparation. This large-scale survey of university students of engineering in three European countries provides important insight into the most relevant language skills, with the goal of informing communicative, task-based curricula for Technical English courses.}, language = {en} } @article{MaierWeihererHuberetal., author = {Maier, Johannes and Weiherer, Maximilian and Huber, Michaela and Palm, Christoph}, title = {Optically tracked and 3D printed haptic phantom hand for surgical training system}, series = {Quantitative Imaging in Medicine and Surgery}, volume = {10}, journal = {Quantitative Imaging in Medicine and Surgery}, number = {02}, publisher = {AME Publishing Company}, address = {Hong Kong, China}, doi = {10.21037/qims.2019.12.03}, pages = {340 -- 455}, abstract = {Background: For surgical fixation of bone fractures of the human hand, so-called Kirschner-wires (K-wires) are drilled through bone fragments. Due to the minimally invasive drilling procedures without a view of risk structures like vessels and nerves, a thorough training of young surgeons is necessary. For the development of a virtual reality (VR) based training system, a three-dimensional (3D) printed phantom hand is required. To ensure an intuitive operation, this phantom hand has to be realistic in both, its position relative to the driller as well as in its haptic features. The softest 3D printing material available on the market, however, is too hard to imitate human soft tissue. Therefore, a support-material (SUP) filled metamaterial is used to soften the raw material. Realistic haptic features are important to palpate protrusions of the bone to determine the drilling starting point and angle. An optical real-time tracking is used to transfer position and rotation to the training system. Methods: A metamaterial already developed in previous work is further improved by use of a new unit cell. Thus, the amount of SUP within the volume can be increased and the tissue is softened further. In addition, the human anatomy is transferred to the entire hand model. A subcutaneous fat layer and penetration of air through pores into the volume simulate shiftability of skin layers. For optical tracking, a rotationally symmetrical marker attached to the phantom hand with corresponding reference marker is developed. In order to ensure trouble-free position transmission, various types of marker point applications are tested. Results: Several cuboid and forearm sample prints lead to a final 30 centimeter long hand model. The whole haptic phantom could be printed faultless within about 17 hours. The metamaterial consisting of the new unit cell results in an increased SUP share of 4.32\%. Validated by an expert surgeon study, this allows in combination with a displacement of the uppermost skin layer a good palpability of the bones. Tracking of the hand marker in dodecahedron design works trouble-free in conjunction with a reference marker attached to the worktop of the training system. Conclusions: In this work, an optically tracked and haptically correct phantom hand was developed using dual-material 3D printing, which can be easily integrated into a surgical training system.}, subject = {Handchirurgie}, language = {en} } @article{NiggPhuMnich, author = {Nigg, Claudio R. and Phu, Tatiana and Mnich, Carina}, title = {Strategies to prevent (STOP) substance use: a website for adolescents in Hawaii}, series = {Journal of Substance Use}, volume = {25}, journal = {Journal of Substance Use}, number = {1}, publisher = {Taylor\&Francis}, doi = {10.1080/14659891.2019.1664659}, pages = {88 -- 94}, abstract = {Background: Adolescent substance use is a global and local (Hawaii) problem. Therefore, the study goal was to develop and investigate the effect of an adolescent substance use prevention intervention website in Hawaii. Methods: A website was developed including drug overviews, health effects, how to stay away, external prevention and treatment resources, and an evaluation. Three grade 11 classes completed a baseline (T1) survey based on website content and a follow-up (T2) assessment after a 15-minute website interaction. - Results: At T1, 63/72 and at T2, 62 students participated (16-17 years old; 92\% female; 87.2\% Filipino). The number correct increased from 48.0\% (SD = 14.5) at T1 to 82.0\% (SD = 15.3) at T2 (t(59) = 13.5, p < .001). Eleven of twelve topics improved (p < .5) which addressed mental disorder drug use, workplace meth-use in Hawaii, Americans in need of drug/alcohol treatment, stimulant drugs, side effects of drugs, drug related domestic/child abuse, short-term drug effects, Hawaii and national methuse, chemicals in drugs, how to stay away, and ways of treatment. Conclusions: Adolescents improved their substance use prevention understanding. This is promising considering the brief, inexpensive, potentially scalable intervention which can be implemented within high school curricula.}, language = {en} } @article{OttPalmVogtetal., author = {Ott, Tankred and Palm, Christoph and Vogt, Robert and Oberprieler, Christoph}, title = {GinJinn: An object-detection pipeline for automated feature extraction from herbarium specimens}, series = {Applications in Plant Sciences}, volume = {8}, journal = {Applications in Plant Sciences}, number = {6}, publisher = {Wiley, Botanical Society of America}, issn = {2168-0450}, doi = {10.1002/aps3.11351}, pages = {e11351}, abstract = {PREMISE: The generation of morphological data in evolutionary, taxonomic, and ecological studies of plants using herbarium material has traditionally been a labor-intensive task. Recent progress in machine learning using deep artificial neural networks (deep learning) for image classification and object detection has facilitated the establishment of a pipeline for the automatic recognition and extraction of relevant structures in images of herbarium specimens. METHODS AND RESULTS: We implemented an extendable pipeline based on state-of-the-art deep-learning object-detection methods to collect leaf images from herbarium specimens of two species of the genus Leucanthemum. Using 183 specimens as the training data set, our pipeline extracted one or more intact leaves in 95\% of the 61 test images. CONCLUSIONS: We establish GinJinn as a deep-learning object-detection tool for the automatic recognition and extraction of individual leaves or other structures from herbarium specimens. Our pipeline offers greater flexibility and a lower entrance barrier than previous image-processing approaches based on hand-crafted features.}, subject = {Deep Learning}, language = {en} } @article{PrantlEigenbergerGehmertetal., author = {Prantl, Lukas and Eigenberger, Andreas and Gehmert, Sebastian and Haerteis, Silke and Aung, Thiha and Rachel, Reinhard and Jung, Ernst Michael and Felthaus, Oliver}, title = {Enhanced Resorption of Liposomal Packed Vitamin C Monitored by Ultrasound}, series = {Journal of Clinical Medicine}, volume = {9}, journal = {Journal of Clinical Medicine}, number = {6}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/jcm9061616}, pages = {1 -- 12}, abstract = {Vitamin C is an essential nutrient for humans and is involved in a plethora of health-related functions. Several studies have shown a connection between vitamin C intake and an improved resistance to infections that involves the immune system. However, the body cannot store vitamin C and both the elevated oral intake, and the intravenous application have certain disadvantages. In this study, we wanted to show a new formulation for the liposomal packaging of vitamin C. Using freeze etching electron microscopy, we show the formed liposomes. With a novel approach of post-processing procedures of real-time sonography that combines enhancement effects by contrast-like ultrasound with a transducer, we wanted to demonstrate the elevated intestinal vitamin C resorption on four participants. With the method presented in this study, it is possible to make use of the liposomal packaging of vitamin C with simple household materials and equipment for intake elevation. For the first time, we show the enhanced resorption of ingested liposomes using microbubble enhanced ultrasound imaging.}, language = {en} } @article{PrantlEigenbergerKleinetal., author = {Prantl, Lukas and Eigenberger, Andreas and Klein, Silvan and Limm, Katharina and Oefner, Peter J. and Schratzenstaller, Thomas and Felthaus, Oliver}, title = {Shear Force Processing of Lipoaspirates for Stem Cell Enrichment Does Not Affect Secretome of Human Cells Detected by Mass Spectrometry In Vitro}, series = {Plastic and Reconstructive Surgery}, volume = {146}, journal = {Plastic and Reconstructive Surgery}, number = {6}, publisher = {American Society of Plastic Surgeons}, doi = {10.1097/PRS.0000000000007343}, pages = {749e -- 758e}, abstract = {Background: Lipofilling is one of the most often performed surgical procedures in plastic and reconstructive surgery. Lipoaspirates provide a ready source of stem cells and secreted factors that contribute to neoangiogenesis and fat graft survival. However, the regulations about the enrichment of these beneficial cells and factors are ambiguous. In this study, the authors tested whether a combination of centrifugation and homogenization allowed the enrichment of viable stem cells in lipoaspirates through the selective removal of tumescent solution, blood, and released lipids without significantly affecting the cell secretome. Methods: Human lipoaspirate was harvested from six different patients using water jet-assisted liposuction. Lipoaspirate was homogenized by first centrifugation (3584 rpm for 2 minutes), shear strain (10 times intersyringe processing), and second centrifugation (3584 rpm for 2 minutes). Stem cell enrichment was shown by cell counting after stem cell isolation. Lipoaspirate from different processing steps (unprocessed, after first centrifugation, after homogenization, after second centrifugation) was incubated in serum-free cell culture medium for mass spectrometric analysis of secreted proteins. Results: Lipoaspirate homogenization leads to a significant 2.6 ± 1.75-fold enrichment attributable to volume reduction without reducing the viability of the stem cells. Protein composition of the secretome did not change significantly after tissue homogenization. Considering the enrichment effects, there were no significant differences in the protein concentration of the 83 proteins found in all processing steps. Conclusions: Stem cells can be enriched mechanically without significantly affecting the composition of secreted proteins. Shear-assisted enrichment of lipoaspirate constitutes no substantial manipulation of the cells' secretome.}, language = {en} } @article{RoggeBaurBlettneretal., author = {Rogge, Alize A. and Baur, Isabel and Blettner, Gabriele and Holtkamp, Ulrike and Horneber, Markus and Jahn, Patrick and Joos, Stefanie and Keberle, Silva and Kettelgerdes, Anita and Klemperer, David and Laengler, Alfred and Voiss, Petra and Weis, Joachim and Witt, Claudia M.}, title = {Defining Criteria for Guiding Cancer Patients to Find a Reputable Complementary Medicine Provider}, series = {Patient Preference and Adherence}, volume = {14}, journal = {Patient Preference and Adherence}, publisher = {DOVE MEDICAL PRESS}, doi = {10.2147/PPA.S230705}, pages = {747 -- 755}, abstract = {Purpose: Even in cases of positive evidence for complementary medicine (CM) therapies, it is still difficult for cancer patients to identify reputable providers. The aim of this study was to develop and evaluate a criteria list to provide guidance to cancer patients seeking a reputable CM provider. Methods: The design combined a literature review, an expert consensus procedure (n=15) and an assessment from three stakeholder perspectives (patients (n=18), CM providers (n=26) and oncology physicians (n=20)). Results: A total of 30 existing CM criteria were extracted from the literature, and 12 more were added by the experts. The main challenge was to define criteria that could easily be applied by the patients. A final comprehensive list of 8 criteria guiding cancer patients to find a reputable CM provider was developed. Conclusion: Health professionals and cancer information services might find the criteria list helpful when aiming to strengthen patients' awareness of quality-related factors associated with CM providers. The criteria developed might be helpful when standards are established for quality assurance in CM in oncology.}, language = {en} } @article{RolfesBittnerFangerauetal., author = {Rolfes, Vasilija and Bittner, Uta and Fangerau, Heiner and Weber, Karsten}, title = {Is it all about revising, correcting, and transferring genes?}, series = {The American Journal of Bioethics}, volume = {20}, journal = {The American Journal of Bioethics}, number = {8}, publisher = {Taylor \& Francis}, doi = {10.1080/15265161.2020.1782526}, pages = {30 -- 32}, 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} } @inproceedings{SeebauerJahnMottok, author = {Seebauer, Stefan and Jahn, Sabrina and Mottok, J{\"u}rgen}, title = {Learning from Escape Rooms? A Study Design Concept Measuring the Effect of a Cryptography Educational Escape Room}, series = {2020 IEEE Global Engineering Education Conference (EDUCON): 27-30 April 2020, Porto, Portugal}, booktitle = {2020 IEEE Global Engineering Education Conference (EDUCON): 27-30 April 2020, Porto, Portugal}, doi = {10.1109/EDUCON45650.2020.9125333}, pages = {1684 -- 1685}, abstract = {Experts predict that more IT-Security specialists will be needed in the coming years, but in current higher education in engineering disciplines, this topic is hardly addressed. Newer learning methods such as game-based learning (GBL) are enjoying an increasing popularity as their improvement in the education of subject specific topics can be proven by a variety of studies. We chose Educational Escape Rooms (EduER) as a GBL-tool to impart IT-Security in higher education of engineers. In our Escape Room (ER), the students try to solve puzzles and riddles with learned knowledge on the emphasis of cryptography. This paper first deals with a brief introduction to GBL and EduERs, followed by the design of our ER concept, containing different tasks with focus on the topic of cryptography. The tasks cover different cryptographic methods and hash algorithms, e.g. AES, RSA, SHA3. Afterwards the experimental study is presented. The study of the EduER was carried out with students from the bachelor's program in Electrical Engineering and Information Technology at the OTH Regensburg. The participants were divided into three groups of 5 to 8 persons each. They received a briefing with important information, followed by the ER execution, a debriefing afterwards and an exam-like evaluation sheet to test their learned knowledge. Finally, first basic results are presented.}, language = {en} } @article{TreutweinLoeschelHippetal., author = {Treutwein, Marius and L{\"o}schel, Rainer and Hipp, Matthias and K{\"o}lbl, Oliver and Dobler, Barbara}, title = {Secondary malignancy risk for patients with localized prostate cancer after intensity-modulated radiotherapy with and without flattening filter}, series = {The Journal of Applied Clinical Medical Physics (JACMP)}, volume = {21}, journal = {The Journal of Applied Clinical Medical Physics (JACMP)}, number = {12}, publisher = {Wiley}, doi = {10.1002/acm2.13088}, pages = {197 -- 205}, abstract = {Men treated for localized prostate cancer by radiotherapy have often a remaining life span of 10 yr or more. Therefore, the risk for secondary malignancies should be taken into account. Plans for ten patients were evaluated which had been performed on an Oncentra (R) treatment planning system for a treatment with an Elekta Synergy (TM) linac with Agility (TM) head. The investigated techniques involved IMRT and VMTA with and without flattening filter. Different dose response models were applied for secondary carcinoma and sarcoma risk in the treated region and also in the periphery. As organs at risk we regarded for carcinoma risk urinary bladder, rectum, colon, esophagus, thyroid, and for sarcoma risk bone and soft tissue. The excess absolute risk (EAR) was found very similar in the treated region for both techniques (IMRT and VMAT) and also for both with and without flattening filter. The secondary sarcoma risk resulted about one magnitude smaller than the secondary carcinoma risk. The EAR to the peripheral organs was statistically significant reduced by application of the flattening filter free mode concerning the flattening filter as main source of scattered dose. Application of flattening filter free mode can thus support to reduce second malignancy risk for patients with localized prostate cancer.}, language = {en} } @article{TreutweinStegerLoescheletal., author = {Treutwein, Marius and Steger, Felix and L{\"o}schel, Rainer and K{\"o}lbl, Oliver and Dobler, Barbara}, title = {The influence of radiotherapy techniques on the plan quality and on the risk of secondary tumors in patients with pituitary adenoma}, series = {BMC cancer}, volume = {20}, journal = {BMC cancer}, publisher = {Springer}, doi = {10.1186/s12885-020-6535-y}, pages = {1 -- 13}, abstract = {BACKGROUND: This planning study compares different radiotherapy techniques for patients with pituitary adenoma, including flatness filter free mode (FFF), concerning plan quality and secondary malignancies for potentially young patients. The flatness filter has been described as main source of photon scatter. MATERIAL AND METHODS: Eleven patients with pituitary adenoma were included. An Elekta Synergy™ linac was used in the treatment planning system Oncentra® and for the measurements. 3D plans, IMRT, and VMAT plans and non-coplanar varieties were considered. The plan quality was evaluated regarding homogeneity, conformity, delivery time and dose to the organs at risk. The secondary malignancy risk was calculated from dose volume data and from measured dose to the periphery using different models for carcinoma and sarcoma risk. RESULTS: The homogeneity and conformity were nearly unchanged with and without flattening filter, neither was the delivery time found substantively different. VMAT plans were more homogenous, conformal and faster in delivery than IMRT plans. The secondary cancer risk was reduced with FFF both in the treated region and in the periphery. VMAT plans resulted in a higher secondary brain cancer risk than IMRT plans, but the risk for secondary peripheral cancer was reduced. Secondary sarcoma risk plays a minor role. No advantage was found for non-coplanar techniques. The FFF delivery times were not shortened due to additional monitor units needed and technical limitations. The risk for secondary brain cancer seems to depend on the irradiated volume. Secondary sarcoma risk is much smaller than carcinoma risk in accordance to the results of the atomic bomb survivors. The reduction of the peripheral dose and resulting secondary malignancy risk for FFF is statistically significant. However, it is negligible in comparison to the risk in the treated region. CONCLUSION: Treatments with FFF can reduce secondary malignancy risk while retaining similar quality as with flattening filter and should be preferred. VMAT plans show the best plan quality combined with lowest peripheral secondary malignancy risk, but highest level of second brain cancer risk. Taking this into account VMAT FFF seems the most advantageous technique for the treatment of pituitary adenomas with the given equipment.}, language = {en} } @article{VisscherWyssSinghetal., author = {Visscher, Rosa and Wyss, C. and Singh, Navrag B. and Taylor, William R. and Dendorfer, Sebastian and Rutz, E. and Brunner, Reinald}, title = {Influence of TAL-TATS surgery on energy production of Tricepts Surae - A musculoskeletal modeling evaluation}, series = {Gait \& Posture}, volume = {81}, journal = {Gait \& Posture}, number = {Suppl. 1}, publisher = {Elsevier}, doi = {10.1016/j.gaitpost.2020.08.090}, pages = {381 -- 382}, language = {en} } @article{WeberMerleNawabietal., author = {Weber, Markus and Merle, Christian and Nawabi, Danyal H. and Dendorfer, Sebastian and Grifka, Joachim and Renkawitz, Tobias}, title = {Inaccurate offset restoration in total hip arthroplasty results in reduced range of motion}, series = {Scientific Reports}, volume = {10}, journal = {Scientific Reports}, number = {13208}, publisher = {Nature}, doi = {10.1038/s41598-020-70059-1}, pages = {9}, abstract = {Offset restoration in total hip arthroplasty (THA) is associated with postoperative range of motion (ROM) and gait kinematics. We aimed to research into the impact of high offset (HO) and standard stems on postoperative ROM. 121 patients received cementless THA through a minimally-invasive anterolateral approach. A 360° hip ROM analysis software calculated impingement-free hip movement based on postoperative 3D-CTs compared to ROM values necessary for activities of daily living (ADL). The same model was then run a second time after changing the stem geometry between standard and HO configuration with the implants in the same position. HO stems showed higher ROM for all directions between 4.6 and 8.9° (p < 0.001) compared with standard stems but with high interindividual variability. In the subgroup with HO stems for intraoperative offset restoration, the increase in ROM was even higher for all ROM directions with values between 6.1 and 14.4° (p < 0.001) compared to offset underrestoration with standard stems. Avoiding offset underrestoration resulted in a higher amount of patients of over 20\% for each ROM direction that fulfilled the criteria for ADL (p < 0.001). In contrast, in patients with standard stems for offset restoration ROM did increase but not clinically relevant by offset overcorrection for all directions between 3.1 and 6.1° (p < 0.001). Offset overcorrection by replacing standard with HO stems improved ROM for ADL in a low number of patients below 10\% (p > 0.03). Patient-individual restoration of offset is crucial for free ROM in THA. Both over and underrestoration of offset should be avoided.}, language = {en} } @inproceedings{WeihererZornWittenbergetal., author = {Weiherer, Maximilian and Zorn, Martin and Wittenberg, Thomas and Palm, Christoph}, title = {Retrospective Color Shading Correction for Endoscopic Images}, series = {Bildverarbeitung f{\"u}r die Medizin 2020. Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 15. bis 17. M{\"a}rz 2020 in Berlin}, booktitle = {Bildverarbeitung f{\"u}r die Medizin 2020. Algorithmen - Systeme - Anwendungen. Proceedings des Workshops vom 15. bis 17. M{\"a}rz 2020 in Berlin}, editor = {Tolxdorff, Thomas and Deserno, Thomas M. and Handels, Heinz and Maier, Andreas and Maier-Hein, Klaus H. and Palm, Christoph}, publisher = {Springer Vieweg}, address = {Wiesbaden}, isbn = {978-3-658-29266-9}, doi = {10.1007/978-3-658-29267-6}, pages = {14 -- 19}, abstract = {In this paper, we address the problem of retrospective color shading correction. An extension of the established gray-level shading correction algorithm based on signal envelope (SE) estimation to color images is developed using principal color components. Compared to the probably most general shading correction algorithm based on entropy minimization, SE estimation does not need any computationally expensive optimization and thus can be implemented more effciently. We tested our new shading correction scheme on artificial as well as real endoscopic images and observed promising results. Additionally, an indepth analysis of the stop criterion used in the SE estimation algorithm is provided leading to the conclusion that a fixed, user-defined threshold is generally not feasible. Thus, we present new ideas how to develop a non-parametric version of the SE estimation algorithm using entropy.}, subject = {Endoskopie}, language = {en} } @article{WiesentSchultheissLullaetal., author = {Wiesent, Lisa and Schultheiß, Ulrich and Lulla, Philipp and Noster, Ulf and Schratzenstaller, Thomas and Schmid, Christof and Nonn, Aida and Spear, Ashley}, title = {Computational analysis of the effects of geometric irregularities and post-processing steps on the mechanical behavior of additively manufactured 316L stainless steel stents}, series = {PLoS ONE}, volume = {15}, journal = {PLoS ONE}, number = {12}, publisher = {PLOS}, doi = {10.1371/journal.pone.0244463}, pages = {1 -- 30}, abstract = {Advances in additive manufacturing enable the production of tailored lattice structures and thus, in principle, coronary stents. This study investigates the effects of process-related irregularities, heat and surface treatment on the morphology, mechanical response, and expansion behavior of 316L stainless steel stents produced by laser powder bed fusion and provides a methodological approach for their numerical evaluation. A combined experimental and computational framework is used, based on both actual and computationally reconstructed laser powder bed fused stents. Process-related morphological deviations between the as-designed and actual laser powder bed fused stents were observed, resulting in a diameter increase by a factor of 2-2.6 for the stents without surface treatment and 1.3-2 for the electropolished stent compared to the as-designed stent. Thus, due to the increased geometrically induced stiffness, the laser powder bed fused stents in the as-built (7.11 ± 0.63 N) or the heat treated condition (5.87 ± 0.49 N) showed increased radial forces when compressed between two plates. After electropolishing, the heat treated stents exhibited radial forces (2.38 ± 0.23 N) comparable to conventional metallic stents. The laser powder bed fused stents were further affected by the size effect, resulting in a reduced yield strength by 41\% in the as-built and by 59\% in the heat treated condition compared to the bulk material obtained from tensile tests. The presented numerical approach was successful in predicting the macroscopic mechanical response of the stents under compression. During deformation, increased stiffness and local stress concentration were observed within the laser powder bed fused stents. Subsequent numerical expansion analysis of the derived stent models within a previously verified numerical model of stent expansion showed that electropolished and heat treated laser powder bed fused stents can exhibit comparable expansion behavior to conventional stents. The findings from this work motivate future experimental/numerical studies to quantify threshold values of critical geometric irregularities, which could be used to establish design guidelines for laser powder bed fused stents/lattice structures.}, subject = {Koronarendoprothese}, language = {en} } @article{ZucchiFrancoSchrecketal., author = {Zucchi, Jose William and Franco, Estefania Aparecida Thome and Schreck, Thomas and Castro Silva, Maria Helena and Migliorini, Sandro Rog{\´e}rio dos Santos and Garcia, T. and Mota, G. A. F. and de Morais, Bruna Evelyn Bueno and Machado, L. H. S. and Batista, A. N. R. and de Pavia, Sergio and de Godoy, I. and Tanni, Suzana}, title = {Different Clusters in Patients with Chronic Obstructive Pulmonary Disease (COPD)}, series = {International Journal of chronic obstructive pulmonary disease}, volume = {15}, journal = {International Journal of chronic obstructive pulmonary disease}, publisher = {Dove Medical Press}, doi = {10.2147/COPD.S268332}, pages = {2847 -- 2856}, abstract = {Background: Chronic obstructive pulmonary disease (COPD) has a functional definition. However, differences in clinical characteristics and systemic manifestations make COPD a heterogeneous disease and some manifestations have been associated with different risks of acute exacerbations, hospitalizations, and death. Objective: Therefore, the objective of the study was to evaluate possible clinical clusters in COPD at two study centers in Brazil and identify the associated exacerbation and mortality rate during 1 year of follow-up. Methods: We included patients with COPD and all underwent an evaluation composed of the Charlson Index, body mass index (BMI), current pharmacological treatment, smoking history (packs-year), history of exacerbations/hospitalizations in the last year, spirometry, six-minute walking test (6MWT), quality of life questionnaires, dyspnea, and hospital anxiety and depression scale. Blood samples were also collected for measurements of C-reactive protein (CRP), blood gases, laboratory analysis, and blood count. For the construction of the clusters, 13 continuous variables of clinical importance were considered: hematocrit, CRP, triglycerides, low density lipoprotein, absolute number of peripheral eosinophils, age, pulse oximetry, BMI, forced expiratory volume in the first second, dyspnea, 6MWD, total score of the Saint George Respiratory Questionnaire and packs-year of smoking. We used the Ward and K-means methods and determined the best silhouette value to identify similarities of individuals within the cluster (cohesion) in relation to the other clusters (separation). The number of clusters was determined by the heterogeneity values of the cluster, which in this case was determined as four clusters. Results: We evaluated 301 COPD patients and identified four different groups of COPD patients. The first cluster (203 patients) was characterized by fewer symptoms and lower functional severity of the disease, the second cluster by higher values of peripheral eosinophils, the third cluster by more systemic inflammation and the fourth cluster by greater obstructive severity and worse gas exchange. Cluster 2 had an average of 959 3 peripheral eosinophils, cluster 3 had a higher prevalence of nutritional depletion (46.1\%), and cluster 4 had a higher BODE index. Regarding the associated comorbidities, we found that only obstructive sleep apnea syndrome and pulmonary thromboembolism were more prevalent in cluster 4. Almost 50\% of all patients presented an exacerbation during 1 year of follow-up. However, it was higher in cluster 4, with 65\% of all patients having at least one exacerbation. The mortality rate was statistically higher in cluster 4, with 26.9\%, vs 9.6\% in cluster 1. Conclusion: We could identify four clinical different clusters in these COPD populations, that were related to different clinical manifestations, comorbidities, exacerbation, and mortality rate. We also identified a specific cluster with higher values of peripheral eosinophils.}, language = {en} }