@inproceedings{KuhlenDigel2017, author = {Kuhlen, Max and Digel, Ilya}, title = {Fluorescence signatures and detection limits of ubiquitous terrestrial bio-compounds}, series = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West}, booktitle = {2nd YRA MedTech Symposium 2017 : June 8th - 9th / 2017 / Hochschule Ruhr-West}, editor = {Erni, Daniel and Fischerauer, Alice and Himmel, J{\"o}rg and Seeger, Thomas and Thelen, Klaus}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-9814801-9-1}, doi = {10.17185/duepublico/43984}, pages = {102 -- 103}, year = {2017}, language = {en} } @article{KuertenKotliarFuestetal.2021, author = {Kuerten, David and Kotliar, Konstantin and Fuest, Matthias and Walter, Peter and Hollstein, Muriel and Plange, Niklas}, title = {Does hemispheric vascular regulation differ significantly in glaucoma patients with altitudinal visual field asymmetry? A single-center, prospective study}, series = {International Ophthalmology}, volume = {41}, journal = {International Ophthalmology}, number = {41}, editor = {Neri, Piergiorgio}, publisher = {Springer}, address = {Berlin}, isbn = {1573-2630}, doi = {10.1007/s10792-021-01876-0}, pages = {3109 -- 3119}, year = {2021}, abstract = {Purpose Vascular risk factors and ocular perfusion are heatedly discussed in the pathogenesis of glaucoma. The retinal vessel analyzer (RVA, IMEDOS Systems, Germany) allows noninvasive measurement of retinal vessel regulation. Significant differences especially in the veins between healthy subjects and patients suffering from glaucoma were previously reported. In this pilot-study we investigated if localized vascular regulation is altered in glaucoma patients with altitudinal visual field defect asymmetry. Methods 15 eyes of 12 glaucoma patients with advanced altitudinal visual field defect asymmetry were included. The mean defect was calculated for each hemisphere separately (-20.99 ± 10.49 pro- found hemispheric visual field defect vs -7.36 ± 3.97 dB less profound hemisphere). After pupil dilation, RVA measurements of retinal arteries and veins were conducted using the standard protocol. The superior and inferior retinal vessel reactivity were measured consecutively in each eye. Results Significant differences were recorded in venous vessel constriction after flicker light stimulation and overall amplitude of the reaction (p \ 0.04 and p \ 0.02 respectively) in-between the hemispheres spheres. Vessel reaction was higher in the hemisphere corresponding to the more advanced visual field defect. Arterial diameters reacted similarly, failing to reach statistical significance. Conclusion Localized retinal vessel regulation is significantly altered in glaucoma patients with asymmetri altitudinal visual field defects. Veins supplying the hemisphere concordant to a less profound visual field defect show diminished diameter changes. Vascular dysregulation might be particularly important in early glaucoma stages prior to a significant visual field defect.}, language = {en} } @article{KuchlerGuenthnerRibeiroetal.2023, author = {Kuchler, Timon and G{\"u}nthner, Roman and Ribeiro, Andrea and Hausinger, Renate and Streese, Lukas and W{\"o}hnl, Anna and Kesseler, Veronika and Negele, Johanna and Assali, Tarek and Carbajo-Lozoya, Javier and Lech, Maciej and Adorjan, Kristina and Stubbe, Hans Christian and Hanssen, Henner and Kotliar, Konstantin and Haller, Berhard and Heemann, Uwe and Schmaderer, Christoph}, title = {Persistent endothelial dysfunction in post-COVID-19 syndrome and its associations with symptom severity and chronic inflammation}, volume = {26}, publisher = {Springer Nature}, address = {Dordrecht}, doi = {10.1007/s10456-023-09885-6}, pages = {547 -- 563}, year = {2023}, abstract = {Background Post-COVID-19 syndrome (PCS) is a lingering disease with ongoing symptoms such as fatigue and cognitive impairment resulting in a high impact on the daily life of patients. Understanding the pathophysiology of PCS is a public health priority, as it still poses a diagnostic and treatment challenge for physicians. Methods In this prospective observational cohort study, we analyzed the retinal microcirculation using Retinal Vessel Analysis (RVA) in a cohort of patients with PCS and compared it to an age- and gender-matched healthy cohort (n = 41, matched out of n = 204). Measurements and main results PCS patients exhibit persistent endothelial dysfunction (ED), as indicated by significantly lower venular flicker-induced dilation (vFID; 3.42\% ± 1.77\% vs. 4.64\% ± 2.59\%; p = 0.02), narrower central retinal artery equivalent (CRAE; 178.1 [167.5-190.2] vs. 189.1 [179.4-197.2], p = 0.01) and lower arteriolar-venular ratio (AVR; (0.84 [0.8-0.9] vs. 0.88 [0.8-0.9], p = 0.007). When combining AVR and vFID, predicted scores reached good ability to discriminate groups (area under the curve: 0.75). Higher PCS severity scores correlated with lower AVR (R = - 0.37 p = 0.017). The association of microvascular changes with PCS severity were amplified in PCS patients exhibiting higher levels of inflammatory parameters. Conclusion Our results demonstrate that prolonged endothelial dysfunction is a hallmark of PCS, and impairments of the microcirculation seem to explain ongoing symptoms in patients. As potential therapies for PCS emerge, RVA parameters may become relevant as clinical biomarkers for diagnosis and therapy management.}, language = {en} } @article{KraemerPitaZhouetal.2009, author = {Kr{\"a}mer, Melina and Pita, Marcos and Zhou, Jian and Ornatska, Maryna and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Katz, Evgeny}, title = {Coupling of Biocomputing Systems with Electronic Chips: Electronic Interface for Transduction of Biochemical Information}, series = {Journal of Physical Chemistry C: Nanomaterials and Interfaces. 113 (2009), H. 6}, journal = {Journal of Physical Chemistry C: Nanomaterials and Interfaces. 113 (2009), H. 6}, publisher = {American Cemical Society}, address = {Washington, DC}, isbn = {1932-7455}, pages = {2573 -- 2579}, year = {2009}, language = {en} } @article{KrottGerhardsSkorupaetal.2011, author = {Krott, Daniel and Gerhards, Michael and Skorupa, Sascha and Sander, Volker}, title = {NHiLA - Bridging the Gap Between .NET and UNICORE}, series = {UNICORE Summit 2011 : proceedings, 7-8 July 2011, Torun, Poland / Mathilde Romberg ... (Eds.)}, journal = {UNICORE Summit 2011 : proceedings, 7-8 July 2011, Torun, Poland / Mathilde Romberg ... (Eds.)}, publisher = {Forschungszentrum J{\"u}lich}, address = {J{\"u}lich}, isbn = {9783893367504}, pages = {77 -- 86}, year = {2011}, language = {en} } @inproceedings{KromeSander2018, author = {Krome, Cornelia and Sander, Volker}, title = {Time series analysis with apache spark and its applications to energy informatics}, series = {Proceedings of the 7th DACH+ Conference on Energy Informatics}, booktitle = {Proceedings of the 7th DACH+ Conference on Energy Informatics}, doi = {10.1186/s42162-018-0043-1}, year = {2018}, abstract = {In energy economy forecasts of different time series are rudimentary. In this study, a prediction for the German day-ahead spot market is created with Apache Spark and R. It is just an example for many different applications in virtual power plant environments. Other examples of use as intraday price processes, load processes of machines or electric vehicles, real time energy loads of photovoltaic systems and many more time series need to be analysed and predicted. This work gives a short introduction into the project where this study is settled. It describes the time series methods that are used in energy industry for forecasts shortly. As programming technique Apache Spark, which is a strong cluster computing technology, is utilised. Today, single time series can be predicted. The focus of this work is on developing a method to parallel forecasting, to process multiple time series simultaneously with R and Apache Spark.}, language = {en} } @article{KromeHoeftSander2019, author = {Krome, Cornelia and H{\"o}ft, Jan and Sander, Volker}, title = {Clustering time series applied to energy markets}, series = {Energy Informatics}, volume = {2}, journal = {Energy Informatics}, number = {Article numer 17}, publisher = {Springer}, address = {Berlin}, issn = {2520-8942}, doi = {10.1186/s42162-019-0076-0}, pages = {1 -- 20}, year = {2019}, language = {en} } @inproceedings{KremersPieper2015, author = {Kremers, Alexander and Pieper, Martin}, title = {Simulation and Verification of Bionic Heat Exchangers with COMSOL Multiphysics® Software}, series = {COMSOL Conference 2015 User Presentations ; COMSOL Conference 2015 Grenoble October 14 - 16, 2015 - World Trade Center, Grenoble, France}, booktitle = {COMSOL Conference 2015 User Presentations ; COMSOL Conference 2015 Grenoble October 14 - 16, 2015 - World Trade Center, Grenoble, France}, publisher = {COMSOL}, address = {G{\"o}ttingen ; Berlin}, pages = {6 Seiten}, year = {2015}, language = {en} } @article{KramerHalamkovaPoghossianetal.2013, author = {Kramer, Friederike and Halamkova, Lenka and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Katz, Evgeny and Halamek, Jan}, title = {Biocatalytic analysis of biomarkers for forensic identification of ethnicity between Caucasian and African American}, series = {The analyst. August 2013}, volume = {Vol. 138}, journal = {The analyst. August 2013}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1364-5528 (E-Journal); 0003-2654 (Print)}, pages = {6251 -- 6257}, year = {2013}, language = {en} } @article{KraftNobisrathSalumaaetal.2004, author = {Kraft, Bodo and Nobisrath, Ulrich and Salumaa, Priit and Schultchen, Erhard}, title = {Fujaba based Tool Development for eHome Systems / Nobisrath, Ulrich ; Salumaa, Priit ; Schultchen, Erhard ; Kraft, Bodo}, series = {Electronic Notes in Theoretical Computer Science. 127 (2004), H. 1}, journal = {Electronic Notes in Theoretical Computer Science. 127 (2004), H. 1}, isbn = {1571-0661}, pages = {89 -- 99}, year = {2004}, language = {en} } @article{KraftHeerRetkowitz2008, author = {Kraft, Bodo and Heer, Thomas and Retkowitz, Daniel}, title = {Algorithm and Tool for Ontology Integration Based on Graph Rewriting / Heer, Thomas ; Retkowitz, Daniel ; Kraft, Bodo}, series = {Applications of Graph Transformations with Industrial Relevance / Third International Symposium, AGTIVE 2007, Kassel, Germany, October 10-12, 2007, Revised Selected and Invited Papers}, journal = {Applications of Graph Transformations with Industrial Relevance / Third International Symposium, AGTIVE 2007, Kassel, Germany, October 10-12, 2007, Revised Selected and Invited Papers}, isbn = {978-3-540-89019-5}, pages = {577 -- 582}, year = {2008}, language = {en} } @article{KraftHeerRetkowitz2008, author = {Kraft, Bodo and Heer, Thomas and Retkowitz, Daniel}, title = {Incremental Ontology Integration / Heer, Thomas ; Retkowitz, Daniel ; Kraft, Bodo}, series = {Proceedings of the 10th International Conference on Enterprise Information Systems : Barcelona, Spain, June 12 - 16, 2008 / organized by INSTICC, Institute for Systems and Technologies of Information, Control and Communication ... [Ed. by Jos{\´e} Cordeiro ...]}, journal = {Proceedings of the 10th International Conference on Enterprise Information Systems : Barcelona, Spain, June 12 - 16, 2008 / organized by INSTICC, Institute for Systems and Technologies of Information, Control and Communication ... [Ed. by Jos{\´e} Cordeiro ...]}, publisher = {INSTICC}, address = {Setubal}, pages = {13 -- 28}, year = {2008}, language = {en} } @article{KozhalakovaZhubanovaMansurovetal.2010, author = {Kozhalakova, A. A. and Zhubanova, Azhar A. and Mansurov, Z. A. and Digel, Ilya and Tazhibayeva, S. M. and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {Adsorption of bacterial lipopolysaccharides on carbonized rice shell}, series = {Science of Central Asia (2010)}, journal = {Science of Central Asia (2010)}, pages = {50 -- 54}, year = {2010}, language = {en} } @article{KowalskiLinderZierkeetal.2016, author = {Kowalski, Julia and Linder, Peter and Zierke, S. and Wulfen, B. van and Clemens, J. and Konstantinidis, K. and Ameres, G. and Hoffmann, R. and Mikucki, J. and Tulaczyk, S. and Funke, O. and Blandfort, D. and Espe, Clemens and Feldmann, Marco and Francke, Gero and Hiecker, S. and Plescher, Engelbert and Sch{\"o}ngarth, Sarah and Dachwald, Bernd and Digel, Ilya and Artmann, Gerhard and Eliseev, D. and Heinen, D. and Scholz, F. and Wiebusch, C. and Macht, S. and Bestmann, U. and Reineking, T. and Zetzsche, C. and Schill, K. and F{\"o}rstner, R. and Niedermeier, H. and Szumski, A. and Eissfeller, B. and Naumann, U. and Helbing, K.}, title = {Navigation technology for exploration of glacier ice with maneuverable melting probes}, series = {Cold Regions Science and Technology}, journal = {Cold Regions Science and Technology}, number = {123}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0165-232X}, doi = {10.1016/j.coldregions.2015.11.006}, pages = {53 -- 70}, year = {2016}, abstract = {The Saturnian moon Enceladus with its extensive water bodies underneath a thick ice sheet cover is a potential candidate for extraterrestrial life. Direct exploration of such extraterrestrial aquatic ecosystems requires advanced access and sampling technologies with a high level of autonomy. A new technological approach has been developed as part of the collaborative research project Enceladus Explorer (EnEx). The concept is based upon a minimally invasive melting probe called the IceMole. The force-regulated, heater-controlled IceMole is able to travel along a curved trajectory as well as upwards. Hence, it allows maneuvers which may be necessary for obstacle avoidance or target selection. Maneuverability, however, necessitates a sophisticated on-board navigation system capable of autonomous operations. The development of such a navigational system has been the focal part of the EnEx project. The original IceMole has been further developed to include relative positioning based on in-ice attitude determination, acoustic positioning, ultrasonic obstacle and target detection integrated through a high-level sensor fusion. This paper describes the EnEx technology and discusses implications for an actual extraterrestrial mission concept.}, language = {en} } @article{KotliarVolkovKoshitsetal.1997, author = {Kotliar, Konstantin and Volkov, V. V. and Koshits, I. N. and Svetlova, O. V.}, title = {Biomekhanicheskie osobennosti vzaimodeĭstviia drenazhno i akkomodatsionnoĭ reguliatornykh sistem glaza v norme i pri kontuzionnom podvyvikhe khrustalika / Volkov, V. V. ; Kotliar, K. E. ; Koshits, I. n. ; Svetlova, O. V. ; Smol´nikov, B. A.}, series = {Vestnik oftalmologii. 113 (1997), H. 3}, journal = {Vestnik oftalmologii. 113 (1997), H. 3}, publisher = {-}, isbn = {0042-465X}, pages = {5 -- 7}, year = {1997}, language = {en} } @article{KotliarVilserNageletal.2004, author = {Kotliar, Konstantin and Vilser, Walthatd and Nagel, Edgar and Lanzl, Ines M.}, title = {Retinal vessel reaction in response to chromatic flickering light / Kotliar, Konstantin E. ; Vilser, Walthard ; Nagel, Edgar ; Lanzl, Ines M.}, series = {Graefe's Archive for Clinical and Experimental Ophthalmology. 242 (2004), H. 5}, journal = {Graefe's Archive for Clinical and Experimental Ophthalmology. 242 (2004), H. 5}, publisher = {-}, isbn = {1435-702X}, pages = {377 -- 392}, year = {2004}, language = {en} } @article{KotliarSvetlovaZinoviewaetal.2001, author = {Kotliar, Konstantin and Svetlova, O. V. and Zinoviewa, N. V. and Krylova, I. S.}, title = {Elaboration of the conception of the biomechanical model of the aqueous intraocular outflow / Svetlova, O. V. ; Zinoviewa, N. V. ; Krylova, I. S. ; Koshitz, I. N. ; Smolnikov, B. A. ; Fedorova, E. M. ; Kotliar, K. E.}, series = {Rossiiskii zhurnal biomekhaniki = Russian Journal of biomechanics. 5 (2001), H. 3}, journal = {Rossiiskii zhurnal biomekhaniki = Russian Journal of biomechanics. 5 (2001), H. 3}, publisher = {-}, isbn = {1812-5123}, pages = {23 -- 27}, year = {2001}, language = {en} } @article{KotliarSvetlovaStegaevetal.2004, author = {Kotliar, Konstantin and Svetlova, O. V. and Stegaev, V. A. and Parkhomov, S. D.}, title = {Biomechanical substantiation of relatively low efficiency of recurrent laser trabeculoplasty / Svetlova, O. V. ; Stagaev, V. A. ; Parkhomov, S. D. ; Kotliar, K. E. ; Makarov, F. N. ; Smolnikov, B. A. ; Koshitz, I. N.}, series = {Glaukoma (2004)}, journal = {Glaukoma (2004)}, publisher = {-}, pages = {29 -- 39}, year = {2004}, language = {en} } @article{KotliarSvetlovaSourjikovetal.2004, author = {Kotliar, Konstantin and Svetlova, O. V. and Sourjikov, A. V. and Zaseeva, M. V.}, title = {Biomechanical peculiarities of aqueous humor production system and outflow regulation system / Svetlova, O. V. ; Sourjikov, A. V. ; Kotliar, K. E. ; Zaseeva, M. V. ; Shukhaev, S. V. ; Koshitz, I. N.}, series = {Glaukoma (2004)}, journal = {Glaukoma (2004)}, publisher = {-}, pages = {66 -- 76}, year = {2004}, language = {en} } @article{KotliarSvetlovaMakarovetal.2003, author = {Kotliar, Konstantin and Svetlova, O. V. and Makarov, F. N. and Zaseeva, M. V.}, title = {Morfologicheskie i funktsional'nye osobennosti resnichnogo poiaska khrustalika kak kliuchevogo ispolnitel'nogo zvena v mekhanizme akkommodatsii glaza cheloveka = Morpho-functional characteristics of lens ciliary body as a key mechanism of accommodation in}, series = {Morfologiia (Saint Petersburg, Russia). 123 (2003), H. 3}, journal = {Morfologiia (Saint Petersburg, Russia). 123 (2003), H. 3}, publisher = {-}, isbn = {1026-3543}, pages = {7 -- 16}, year = {2003}, language = {en} } @article{KotliarOrtnerConradietal.2022, author = {Kotliar, Konstantin and Ortner, Marion and Conradi, Anna and Hacker, Patricia and Hauser, Christine and G{\"u}nthner, Roman and Moser, Michaela and Muggenthaler, Claudia and Diehl-Schmid, Janine and Priller, Josef and Schmaderer, Christoph and Grimmer, Timo}, title = {Altered retinal cerebral vessel oscillation frequencies in Alzheimer's disease compatible with impaired amyloid clearance}, series = {Neurobiology of Aging}, volume = {120}, journal = {Neurobiology of Aging}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0197-4580}, doi = {10.1016/j.neurobiolaging.2022.08.012}, pages = {117 -- 127}, year = {2022}, abstract = {Retinal vessels are similar to cerebral vessels in their structure and function. Moderately low oscillation frequencies of around 0.1 Hz have been reported as the driving force for paravascular drainage in gray matter in mice and are known as the frequencies of lymphatic vessels in humans. We aimed to elucidate whether retinal vessel oscillations are altered in Alzheimer's disease (AD) at the stage of dementia or mild cognitive impairment (MCI). Seventeen patients with mild-to-moderate dementia due to AD (ADD); 23 patients with MCI due to AD, and 18 cognitively healthy controls (HC) were examined using Dynamic Retinal Vessel Analyzer. Oscillatory temporal changes of retinal vessel diameters were evaluated using mathematical signal analysis. Especially at moderately low frequencies around 0.1 Hz, arterial oscillations in ADD and MCI significantly prevailed over HC oscillations and correlated with disease severity. The pronounced retinal arterial vasomotion at moderately low frequencies in the ADD and MCI groups would be compatible with the view of a compensatory upregulation of paravascular drainage in AD and strengthen the amyloid clearance hypothesis.}, language = {en} } @article{KotliarNagelVilseretal.2010, author = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Seidova, Seid-Fatima and Lanzl, Ines}, title = {Microstructural alterations of retinal arterial blood column along the vessel axis in systemic hypertension}, series = {Investigative Ophthalmology \& Visual Science, IOVS}, volume = {51}, journal = {Investigative Ophthalmology \& Visual Science, IOVS}, number = {4}, publisher = {ARVO}, address = {Rockville, Md.}, issn = {0146-0404}, doi = {10.1167/iovs.09-3649}, pages = {2165 -- 2172}, year = {2010}, abstract = {Purpose: Image analysis by the retinal vessel analyzer (RVA) observes retinal vessels in their dynamic state online noninvasively along a chosen vessel segment. It has been found that high-frequency diameter changes in the retinal artery blood column along the vessel increase significantly in anamnestically healthy volunteers with increasing age and in patients with glaucoma during vascular dilation. This study was undertaken to investigate whether longitudinal sections of the retinal artery blood column are altered in systemic hypertension. Methods: Retinal arteries of 15 untreated patients with essential arterial hypertension (age, 50.9 ± 11.9 years) and of 15 age-matched anamnestically healthy volunteers were examined by RVA. After baseline assessment, a monochromatic luminance flicker (530-600 nm; 12.5 Hz; 20 s) was applied to evoke retinal vasodilation. Differences in amplitude and frequency of spatial artery blood column diameter change along segments (longitudinal arterial profiles) of 1 mm in length were measured and analyzed using Fourier transformation. Results: In the control group, average reduced power spectra (ARPS) of longitudinal arterial profiles did not differ when arteries changed from constriction to dilation. In the systemic hypertension group, ARPS during constriction, baseline, and restoration were identical and differed from ARPS during dilation (P < 0.05). Longitudinal arterial profiles in both groups showed significant dissimilitude at baseline and restoration (P < 0.05). Conclusions: The retinal artery blood column demonstrates microstructural alterations in systemic hypertension and is less irregular along the vessel axis during vessel dilation. These microstructural changes may be an indication of alterations in vessel wall rigidity, vascular endothelial function, and smooth muscle cells in this disease, leading to impaired perfusion and regulation.}, language = {en} } @article{KotliarNagelVilseretal.2008, author = {Kotliar, Konstantin and Nagel, Edgar and Vilser, Walthard and Lanzl, Ines M.}, title = {Functional in vivo assessment of retinal artery microirregularities in glaucoma / Kotliar, Konstantin E. ; Nagel, Edgar ; Vilser, Walthard ; Lanzl, Ines M.}, series = {Acta Ophthalmologica. 86 (2008), H. 4}, journal = {Acta Ophthalmologica. 86 (2008), H. 4}, publisher = {-}, isbn = {1755-3768}, pages = {424 -- 433}, year = {2008}, language = {en} } @article{KotliarMueckeVilseretal.2008, author = {Kotliar, Konstantin and M{\"u}cke, Bruno and Vilser, Walthard and Schilling, Rudolf}, title = {Effect of aging on retinal artery blood column diameter measured along the vessel axis / Kotliar, Konstantin E. ; M{\"u}cke, Bruno ; Vilser, Walthard ; Schilling, Rudolf ; Lanzl, Ines M.}, series = {Investigative Ophthalmology \& Visual Science, IOVS. 49 (2008), H. 5}, journal = {Investigative Ophthalmology \& Visual Science, IOVS. 49 (2008), H. 5}, publisher = {-}, isbn = {0146-0404}, pages = {2094 -- 2102}, year = {2008}, language = {en} } @article{KotliarMogilevskiĭShiloetal.2008, author = {Kotliar, Konstantin and Mogilevskiĭ, A. Ia. and Shilo, A. V. and Panchekha, A. P.}, title = {[Chaotic non-linear dynamics of alpha-band of the EEg and organization of the cortical activity of P300 wave] / Mogilevskiĭ, A. Ia. ; Kotliar, K. E. ; Shilo, A. V. ; Panchekha, A. P.}, series = {Zhurnal vyssheĭ nervnoĭ deiatelnosti imeni I P Pavlova. 58 (2008), H. 5}, journal = {Zhurnal vyssheĭ nervnoĭ deiatelnosti imeni I P Pavlova. 58 (2008), H. 5}, publisher = {-}, isbn = {0044-4677}, pages = {562 -- 575}, year = {2008}, language = {en} } @article{KotliarMaierBaueretal.2008, author = {Kotliar, Konstantin and Maier, Mathias and Bauer, Svetlana and Feucht, Nikolaus and Lohmann, Chris and Lanzl, Ines}, title = {Intravitreal injection of triamcinolone acetonide and intraocular pressure: author's reply}, series = {Acta Ophthalmologica}, volume = {86}, journal = {Acta Ophthalmologica}, number = {6}, publisher = {-}, isbn = {1755-3768}, pages = {692 -- 693}, year = {2008}, language = {en} } @article{KotliarMaierBaueretal.2007, author = {Kotliar, Konstantin and Maier, Mathias and Bauer, Svetlana and Feucht, Nikolaus}, title = {Effect of intravitreal injections and volume changes on intraocular pressure: clinical results and biomechanical model / Kotliar, Konstantin ; Maier, Mathias ; Bauer, Svetlana ; Feucht, Nikolaus ; Lohmann, Chris ; Lanzl, Ines}, series = {Acta Ophthalmologica Scandinavica. 85 (2007), H. 7}, journal = {Acta Ophthalmologica Scandinavica. 85 (2007), H. 7}, publisher = {-}, isbn = {1755-3768}, pages = {777 -- 781}, year = {2007}, language = {en} } @article{KotliarLanzlSchmidtTrucksaessetal.2011, author = {Kotliar, Konstantin and Lanzl, Ines M. and Schmidt-Trucks{\"a}ss, A. and Sitnikova, Diana and Ali, Mohammad and Blume, Katharina and Halle, Martin and Hansser, Henner}, title = {Dynamic retinal vessel response to flicker in obesity: A methodological approach}, series = {Microvascular Research}, volume = {81}, journal = {Microvascular Research}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0026-2862}, pages = {123 -- 128}, year = {2011}, language = {en} } @article{KotliarLanzlMaieretal.2008, author = {Kotliar, Konstantin and Lanzl, Ines M. and Maier, Mathias and Feucht, Nikolaus}, title = {Intraocular pressure effects of pegaptanib (macugen) injections in patients with and without glaucoma / Lanzl, Ines M. ; Maier, Mathias ; Feucht, Nikolaus ; Lohmann, Chris P. ; Kotliar, Konstantin E.}, series = {American Journal of Ophthalmology . 145 (2008), H. 1}, journal = {American Journal of Ophthalmology . 145 (2008), H. 1}, publisher = {-}, isbn = {1879-1891}, pages = {185 -- 185}, year = {2008}, language = {en} } @article{KotliarLanzlHanssenetal.2012, author = {Kotliar, Konstantin and Lanzl, Ines M. and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Halle, Martin and Heemann, Uwe and Schmidt-Trucks{\"a}ss, Arno and Baumann, Marcus}, title = {Does increased blood pressure rather than aging influence retinal pulse wave velocity?}, series = {Investigative Ophthalmology \& Visual Science, IOVS}, volume = {53}, journal = {Investigative Ophthalmology \& Visual Science, IOVS}, number = {4}, publisher = {ARVO}, address = {Rockville, Md.}, issn = {0146-0404}, doi = {10.1167/iovs.11-8815}, pages = {2119 -- 2126}, year = {2012}, abstract = {Purpose: It was demonstrated previously that retinal pulse wave velocity (rPWV) as a measure of retinal arterial stiffness is increased in aged anamnestically healthy volunteers compared with young healthy subjects. Using novel methodology of rPWV assessment this finding was confirmed and investigated whether it might relate to the increased blood pressure usually accompanying the aging process, rather than to the aging itself. Methods: A total of 12 young 25.5-year-old (24.0-28.8) [median(1st quartile-3rd quartile)] and 12 senior 68.5-year-old (63.8-71.8) anamnestically healthy volunteers; and 12 senior 63.0-year-old (60.8-65.0) validated healthy volunteers and 12 young 33.0-year-old (29.5-35.0) hypertensive patients were examined. Time-dependent alterations of vessel diameter were assessed by the Dynamic Vessel Analyzer in a retinal artery of each subject. The data were filtered and processed using mathematical signal analysis and rPWVs were calculated. Results: rPWV amounted to 1200 (990-1470) RU (relative units)/s in the hypertensive group and to 1040 (700-2230) RU/s in anamnestically healthy seniors. These differed significantly from rPWVs in young healthy group (410 [280-500] RU/s) and in validated healthy seniors (400 [320-510] RU/s). rPWV associated with age and mean arterial pressure (MAP) in the pooled cohort excluded validated healthy seniors. In a regression model these associations remain when alternately adjusted for MAP and age. When including validated healthy seniors in the pooled cohort only association with MAP remains. Conclusions: Both aging (with not excluded cardiovascular risk factors) and mild hypertension are associated with elevated rPWV. rPWV increases to a similar extent both in young mildly hypertensive subjects and in aged anamnestically healthy persons. Healthy aging is not associated with increased rPWV.}, language = {en} } @article{KotliarLanzl2011, author = {Kotliar, Konstantin and Lanzl, Ines M.}, title = {Can vascular function be assessed by the interpretation of retinal vascular diameter changes?}, series = {Investigative Ophthalmology \& Visual Science, IOVS. 52 (2011), H. 1}, journal = {Investigative Ophthalmology \& Visual Science, IOVS. 52 (2011), H. 1}, publisher = {ARVO}, address = {Rockville, Md.}, isbn = {0146-0404}, pages = {635 -- 636}, year = {2011}, language = {en} } @article{KotliarKozlovaLanzl2009, author = {Kotliar, Konstantin and Kozlova, Tatiana V. and Lanzl, Ines M.}, title = {Postoperative aqueous outflow in the human eye after glaucoma filtration surgery: biofluidmechanical considerations}, series = {Biomedizinische Technik = Biomedical Engineering}, volume = {54}, journal = {Biomedizinische Technik = Biomedical Engineering}, number = {1}, publisher = {-}, isbn = {1862-278X}, pages = {14 -- 22}, year = {2009}, language = {en} } @article{KotliarKoshitzSvetlowaetal.2006, author = {Kotliar, Konstantin and Koshitz, I. N. and Svetlowa, O. V. and Zaseeva, M. V.}, title = {Physiological principles of hypotensive therapy of open-angle glaucoma during presbyopic period. Part II Promising algorithms of practical sparing applications / Koshitz, I. N. ; Svetlova, O. V. ; Zaseeva, M. V. ; Shuhaev, S. V. ; Makarov, F. N. ; Kotliar}, series = {Glaukoma (2006)}, journal = {Glaukoma (2006)}, publisher = {-}, pages = {51 -- 70}, year = {2006}, language = {en} } @article{KotliarKoshitzSvetlowaetal.2005, author = {Kotliar, Konstantin and Koshitz, I. N. and Svetlowa, O. V. and Makarov, F. N.}, title = {Biomechanical analysis of traditional and contemporary conceptions on pathogenesis of the primary open angle glaucoma / Koshitz, I. N. ; Svetlova, O. V. ; Kotliar, K. E. ; Makarov, F. N. ; Smolnikov, B. A.}, series = {Glaukoma (2005)}, journal = {Glaukoma (2005)}, publisher = {-}, pages = {41 -- 63}, year = {2005}, language = {en} } @article{KotliarKoshitzSvetlovaetal.2006, author = {Kotliar, Konstantin and Koshitz, I. N. and Svetlova, O. V. and Zaseeva, M. V.}, title = {Physiological principles of hypotensive therapy of open-angle glaucoma during presbyopic period. Part I Initial theoretical presuppositions, hypotheses and facts / Koshitz, I. N. ; Svetlova, O. V. ; Zaseeva, M. V. ; Shuhaev, S. V. ; Makarov, F. N. ; Kotli}, series = {Glaukoma (2006)}, journal = {Glaukoma (2006)}, publisher = {-}, pages = {35 -- 53}, year = {2006}, language = {en} } @article{KotliarKharoubiSchmidtTrucksaessetal.2009, author = {Kotliar, Konstantin and Kharoubi, A. and Schmidt-Trucks{\"a}ß, A. and Halle, M. and Lanzl, I.}, title = {Does internal longitudinal microstructure of retinal veins change with age in medically healthy persons?}, series = {Acta Ophthalmologica}, volume = {Vol. 87}, journal = {Acta Ophthalmologica}, number = {Suppl. S244}, publisher = {Wiley}, address = {Weinheim}, issn = {1600-0420 (E-Journal); 1755-3768 (E-Journal); 0001-639X (Print); 1395-3907 (Print); 1755-375X (Print)}, pages = {0}, year = {2009}, language = {en} } @article{KotliarHauserOrtneretal.2017, author = {Kotliar, Konstantin and Hauser, Christine and Ortner, Marion and Muggenthaler, Claudia and Diehl-Schmid, Janine and Angermann, Susanne and Hapfelmeier, Alexander and Schmaderer, Christoph and Grimmer, Timo}, title = {Altered neurovascular coupling as measured by optical imaging: a biomarker for Alzheimer's disease}, series = {Scientific Reports}, volume = {7}, journal = {Scientific Reports}, number = {1}, publisher = {Springer Nature}, address = {Cham}, issn = {2045-2322}, doi = {10.1038/s41598-017-13349-5}, pages = {1 -- 11}, year = {2017}, language = {en} } @article{KotliarHanssenEberhardtetal.2013, author = {Kotliar, Konstantin and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Schmaderer, Christoph and Halle, Martin and Heemann, Uwe and Baumann, M.}, title = {Retinal pulse wave velocity in young male normotensive and mildly hypertensive subjects}, series = {Microcirculation}, journal = {Microcirculation}, publisher = {Wiley}, address = {Malden}, issn = {1549-8719}, year = {2013}, language = {en} } @article{KotliarBaumannVilseretal.2011, author = {Kotliar, Konstantin and Baumann, Marcus and Vilser, Walthard and Lanzl, Ines M.}, title = {Pulse wave velocity in retinal arteries of healthy volunteers}, series = {British Journal of Ophthalmology (eBJO)}, volume = {95}, journal = {British Journal of Ophthalmology (eBJO)}, number = {11}, publisher = {BMJ Publ. Group}, address = {London}, isbn = {1468-2079}, pages = {675 -- 679}, year = {2011}, language = {en} } @article{KotliarBauerZamuraev2006, author = {Kotliar, Konstantin and Bauer, S. M. and Zamuraev, L. A.}, title = {Model of the transversely isotropic spherical layer for estimation of intraocular pressure changes after intravitreal injections / Bauer, S. M. ; Zamuraev, L. A. ; Kotliar, K. E.}, series = {Rossiiskii zhurnal biomekhaniki = Russian Journal of biomechanics. 10 (2006), H. 2}, journal = {Rossiiskii zhurnal biomekhaniki = Russian Journal of biomechanics. 10 (2006), H. 2}, publisher = {-}, isbn = {1812-5123}, pages = {41 -- 47}, year = {2006}, language = {en} } @phdthesis{Kotliar2008, author = {Kotliar, Konstantin}, title = {Functional in-vivo assessment and biofluidmechanical analysis of age-related and pathological microstructural changes in retinal vessels [Elektronische Ressource]}, publisher = {-}, year = {2008}, language = {en} } @incollection{Kotliar2021, author = {Kotliar, Konstantin}, title = {Ocular rigidity: clinical approach}, series = {Ocular Rigidity, Biomechanics and Hydrodynamics of the Eye}, booktitle = {Ocular Rigidity, Biomechanics and Hydrodynamics of the Eye}, editor = {Pallikaris, I. and Tsilimbaris, M. K. and Dastiridou, A. I.}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-64422-2}, doi = {10.1007/978-3-030-64422-2_2}, pages = {15 -- 43}, year = {2021}, abstract = {The term ocular rigidity is widely used in clinical ophthalmology. Generally it is assumed as a resistance of the whole eyeball to mechanical deformation and relates to biomechanical properties of the eye and its tissues. Basic principles and formulas for clinical tonometry, tonography and pulsatile ocular blood flow measurements are based on the concept of ocular rigidity. There is evidence for altered ocular rigidity in aging, in several eye diseases and after eye surgery. Unfortunately, there is no consensual view on ocular rigidity: it used to make a quite different sense for different people but still the same name. Foremost there is no clear consent between biomechanical engineers and ophthalmologists on the concept. Moreover ocular rigidity is occasionally characterized using various parameters with their different physical dimensions. In contrast to engineering approach, clinical approach to ocular rigidity claims to characterize the total mechanical response of the eyeball to its deformation without any detailed considerations on eye morphology or material properties of its tissues. Further to the previous chapter this section aims to describe clinical approach to ocular rigidity from the perspective of an engineer in an attempt to straighten out this concept, to show its advantages, disadvantages and various applications.}, language = {en} } @article{KoppSchunckGosauetal.2020, author = {Kopp, Alexander and Schunck, Laura and Gosau, Martin and Smeets, Ralf and Burg, Simon and Fuest, Sandra and Kr{\"o}ger, Nadja and Zinser, Max and Krohn, Sebastian and Behbahani, Mehdi and K{\"o}pf, Marius and Lauts, Lisa and Rutkowski, Rico}, title = {Influence of the casting concentration on the mechanical and optical properties of Fa/CaCl2-derived silk fibroin membranes}, series = {International Journal of Molecular Sciences}, volume = {21}, journal = {International Journal of Molecular Sciences}, number = {18 art. no. 6704}, publisher = {MDPI}, address = {Basel}, issn = {1422-0067}, doi = {10.3390/ijms21186704}, year = {2020}, abstract = {In this study, we describe the manufacturing and characterization of silk fibroin membranes derived from the silkworm Bombyx mori. To date, the dissolution process used in this study has only been researched to a limited extent, although it entails various potential advantages, such as reduced expenses and the absence of toxic chemicals in comparison to other conventional techniques. Therefore, the aim of this study was to determine the influence of different fibroin concentrations on the process output and resulting membrane properties. Casted membranes were thus characterized with regard to their mechanical, structural and optical assets via tensile testing, SEM, light microscopy and spectrophotometry. Cytotoxicity was evaluated using BrdU, XTT, and LDH assays, followed by live-dead staining. The formic acid (FA) dissolution method was proven to be suitable for the manufacturing of transparent and mechanically stable membranes. The fibroin concentration affects both thickness and transparency of the membranes. The membranes did not exhibit any signs of cytotoxicity. When compared to other current scientific and technical benchmarks, the manufactured membranes displayed promising potential for various biomedical applications. Further research is nevertheless necessary to improve reproducible manufacturing, including a more uniform thickness, less impurity and physiological pH within the membranes.}, language = {en} } @article{KoppSchmeetsGosauetal.2019, author = {Kopp, Alexander and Schmeets, Ralf and Gosau, Martin and Friedrich, Reinhard E. and Fuest, Sandra and Behbahani, Mehdi and Barbeck, Mike and Rutkowski, Rico and Burg, Simon and Kluwe, Lan and Henningsen, Anders}, title = {Production and Characterization of Porous Fibroin Scaffolds for Regenerative Medical Application}, series = {In Vivo}, volume = {33}, journal = {In Vivo}, number = {3}, issn = {1791-7549}, doi = {10.21873/invivo.11536}, pages = {757 -- 762}, year = {2019}, language = {en} } @inproceedings{KolditzAlbrachtFasseetal.2015, author = {Kolditz, Melanie and Albracht, Kirsten and Fasse, Alessandro and Albin, Thivaharan and Br{\"u}ggemann, Gert-Peter and Abel, Dirk}, title = {Evaluation of an industrial robot as a leg press training device}, series = {XV International Symposium on Computer Simulation in Biomechanics July 9th - 11th 2015, Edinburgh, UK}, booktitle = {XV International Symposium on Computer Simulation in Biomechanics July 9th - 11th 2015, Edinburgh, UK}, pages = {41 -- 42}, year = {2015}, language = {en} } @inproceedings{KolditzAlbinFasseetal.2015, author = {Kolditz, Melanie and Albin, Thivaharan and Fasse, Alessandro and Br{\"u}ggemann, Gert-Peter and Abel, Dirk and Albracht, Kirsten}, title = {Simulative Analysis of Joint Loading During Leg Press Exercise for Control Applications}, series = {IFAC-PapersOnLine}, volume = {48}, booktitle = {IFAC-PapersOnLine}, number = {20}, doi = {10.1016/j.ifacol.2015.10.179}, pages = {435 -- 440}, year = {2015}, language = {en} } @article{KolditzAlbinAbeletal.2016, author = {Kolditz, Melanie and Albin, Thivaharan and Abel, Dirk and Fasse, Alessandro and Br{\"u}ggemann, Gert-Peter and Albracht, Kirsten}, title = {Evaluation of foot position and orientation as manipulated variables to control external knee adduction moments in leg extension training}, series = {Computer methods and programs in biomedicine}, volume = {171}, journal = {Computer methods and programs in biomedicine}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0169-2607}, doi = {10.1016/j.cmpb.2016.09.005}, pages = {81 -- 86}, year = {2016}, abstract = {Background and Objective Effective leg extension training at a leg press requires high forces, which need to be controlled to avoid training-induced damage. In order to avoid high external knee adduction moments, which are one reason for unphysiological loadings on knee joint structures, both training movements and the whole reaction force vector need to be observed. In this study, the applicability of lateral and medial changes in foot orientation and position as possible manipulated variables to control external knee adduction moments is investigated. As secondary parameters both the medio-lateral position of the center of pressure and the frontal-plane orientation of the reaction force vector are analyzed. Methods Knee adduction moments are estimated using a dynamic model of the musculoskeletal system together with the measured reaction force vector and the motion of the subject by solving the inverse kinematic and dynamic problem. Six different foot conditions with varying positions and orientations of the foot in a static leg press are evaluated and compared to a neutral foot position. Results Both lateral and medial wedges under the foot and medial and lateral shifts of the foot can influence external knee adduction moments in the presented study with six healthy subjects. Different effects are observed with the varying conditions: the pose of the leg is changed and the direction and center of pressure of the reaction force vector is influenced. Each effect results in a different direction or center of pressure of the reaction force vector. Conclusions The results allow the conclusion that foot position and orientation can be used as manipulated variables in a control loop to actively control knee adduction moments in leg extension training.}, language = {en} } @inproceedings{KohlSchmidtsKloeseretal.2021, author = {Kohl, Philipp and Schmidts, Oliver and Kl{\"o}ser, Lars and Werth, Henri and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {STAMP 4 NLP - an agile framework for rapid quality-driven NLP applications development}, series = {Quality of Information and Communications Technology. QUATIC 2021}, booktitle = {Quality of Information and Communications Technology. QUATIC 2021}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-85346-4}, doi = {10.1007/978-3-030-85347-1_12}, pages = {156 -- 166}, year = {2021}, abstract = {The progress in natural language processing (NLP) research over the last years, offers novel business opportunities for companies, as automated user interaction or improved data analysis. Building sophisticated NLP applications requires dealing with modern machine learning (ML) technologies, which impedes enterprises from establishing successful NLP projects. Our experience in applied NLP research projects shows that the continuous integration of research prototypes in production-like environments with quality assurance builds trust in the software and shows convenience and usefulness regarding the business goal. We introduce STAMP 4 NLP as an iterative and incremental process model for developing NLP applications. With STAMP 4 NLP, we merge software engineering principles with best practices from data science. Instantiating our process model allows efficiently creating prototypes by utilizing templates, conventions, and implementations, enabling developers and data scientists to focus on the business goals. Due to our iterative-incremental approach, businesses can deploy an enhanced version of the prototype to their software environment after every iteration, maximizing potential business value and trust early and avoiding the cost of successful yet never deployed experiments.}, language = {en} } @inproceedings{KohlFreyerKraemeretal.2023, author = {Kohl, Philipp and Freyer, Nils and Kr{\"a}mer, Yoka and Werth, Henri and Wolf, Steffen and Kraft, Bodo and Meinecke, Matthias and Z{\"u}ndorf, Albert}, title = {ALE: a simulation-based active learning evaluation framework for the parameter-driven comparison of query strategies for NLP}, series = {Deep Learning Theory and Applications. DeLTA 2023. Communications in Computer and Information Science}, booktitle = {Deep Learning Theory and Applications. DeLTA 2023. Communications in Computer and Information Science}, editor = {Conte, Donatello and Fred, Ana and Gusikhin, Oleg and Sansone, Carlo}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-39058-6 (Print)}, doi = {978-3-031-39059-3}, pages = {235 -- 253}, year = {2023}, abstract = {Supervised machine learning and deep learning require a large amount of labeled data, which data scientists obtain in a manual, and time-consuming annotation process. To mitigate this challenge, Active Learning (AL) proposes promising data points to annotators they annotate next instead of a subsequent or random sample. This method is supposed to save annotation effort while maintaining model performance. However, practitioners face many AL strategies for different tasks and need an empirical basis to choose between them. Surveys categorize AL strategies into taxonomies without performance indications. Presentations of novel AL strategies compare the performance to a small subset of strategies. Our contribution addresses the empirical basis by introducing a reproducible active learning evaluation (ALE) framework for the comparative evaluation of AL strategies in NLP. The framework allows the implementation of AL strategies with low effort and a fair data-driven comparison through defining and tracking experiment parameters (e.g., initial dataset size, number of data points per query step, and the budget). ALE helps practitioners to make more informed decisions, and researchers can focus on developing new, effective AL strategies and deriving best practices for specific use cases. With best practices, practitioners can lower their annotation costs. We present a case study to illustrate how to use the framework.}, language = {en} } @article{KodomskoiKotliarSchroederetal.2019, author = {Kodomskoi, Leonid and Kotliar, Konstantin and Schr{\"o}der, Andreas and Weiss, Michael and Hille, Konrad}, title = {Suture-Probe Canaloplasty as an Alternative to Canaloplasty using the iTrack™ Microcatheter}, series = {Journal of Glaucoma}, journal = {Journal of Glaucoma}, number = {Epub ahead of print}, publisher = {Lippincott Williams \& Wilkins}, address = {Philadelphia}, issn = {1057-0829}, doi = {10.1097/IJG.0000000000001321}, year = {2019}, language = {en} } @incollection{KochPoghossianWegeetal.2018, author = {Koch, Claudia and Poghossian, Arshak and Wege, Christina and Sch{\"o}ning, Michael Josef}, title = {TMV-Based Adapter Templates for Enhanced Enzyme Loading in Biosensor Applications}, series = {Virus-Derived Nanoparticles for Advanced Technologies}, booktitle = {Virus-Derived Nanoparticles for Advanced Technologies}, editor = {Wege, Christina}, publisher = {Humana Press}, address = {New York, NY}, isbn = {978-1-4939-7808-3}, doi = {10.1007/978-1-4939-7808-3}, pages = {553 -- 568}, year = {2018}, abstract = {Nanotubular tobacco mosaic virus (TMV) particles and RNA-free lower-order coat protein (CP) aggregates have been employed as enzyme carriers in different diagnostic layouts and compared for their influence on biosensor performance. In the following, we describe a label-free electrochemical biosensor for improved glucose detection by use of TMV adapters and the enzyme glucose oxidase (GOD). A specific and efficient immobilization of streptavidin-conjugated GOD ([SA]-GOD) complexes on biotinylated TMV nanotubes or CP aggregates was achieved via bioaffinity binding. Glucose sensors with adsorptively immobilized [SA]-GOD, and with [SA]-GOD cross-linked with glutardialdehyde, respectively, were tested in parallel on the same sensor chip. Comparison of these sensors revealed that TMV adapters enhanced the amperometric glucose detection remarkably, conveying highest sensitivity, an extended linear detection range and fastest response times. These results underline a great potential of an integration of virus/biomolecule hybrids with electronic transducers for applications in biosensorics and biochips. Here, we describe the fabrication and use of amperometric sensor chips combining an array of circular Pt electrodes, their loading with GOD-modified TMV nanotubes (and other GOD immobilization methods), and the subsequent investigations of the sensor performance.}, language = {en} } @article{KochPoghossianSchoeningetal.2018, author = {Koch, Claudia and Poghossian, Arshak and Sch{\"o}ning, Michael Josef and Wege, Christian}, title = {Penicillin Detection by Tobacco Mosaic Virus-Assisted Colorimetric Biosensors}, series = {Nanotheranostics}, volume = {2}, journal = {Nanotheranostics}, number = {2}, publisher = {Ivyspring}, address = {Sydney}, issn = {2206-7418}, doi = {10.7150/ntno.22114}, pages = {184 -- 196}, year = {2018}, abstract = {The presentation of enzymes on viral scaffolds has beneficial effects such as an increased enzyme loading and a prolonged reusability in comparison to conventional immobilization platforms. Here, we used modified tobacco mosaic virus (TMV) nanorods as enzyme carriers in penicillin G detection for the first time. Penicillinase enzymes were conjugated with streptavidin and coupled to TMV rods by use of a bifunctional biotin-linker. Penicillinase-decorated TMV particles were characterized extensively in halochromic dye-based biosensing. Acidometric analyte detection was performed with bromcresol purple as pH indicator and spectrophotometry. The TMV-assisted sensors exhibited increased enzyme loading and strongly improved reusability, and higher analysis rates compared to layouts without viral adapters. They extended the half-life of the sensors from 4 - 6 days to 5 weeks and thus allowed an at least 8-fold longer use of the sensors. Using a commercial budget-priced penicillinase preparation, a detection limit of 100 µM penicillin was obtained. Initial experiments also indicate that the system may be transferred to label-free detection layouts.}, language = {en} } @article{KnoxBruggemannGossmannetal.2020, author = {Knox, Ronald and Bruggemann, Andrea and Gossmann, Matthias and Thomas, Ulrich and Horv{\´a}th, Andr{\´a}s and Dragicevic, Elena and Stoelzle-Feix, Sonja and Fertig, Niels and Jung, Alexander and Raman, Aravind Hariharan and Staat, Manfred and Linder, Peter}, title = {Combining physiological relevance and throughput for in vitro cardiac contractility measurement}, series = {Biophysical Journal}, volume = {118}, journal = {Biophysical Journal}, number = {Issue 3, Supplement 1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0006-3495}, doi = {10.1016/j.bpj.2019.11.3104}, pages = {570a}, year = {2020}, abstract = {Despite increasing acceptance of human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) in safety pharmacology, controversy remains about the physiological relevance of existing in vitro models for their mechanical testing. We hypothesize that existing signs of immaturity of the cell models result from an improper mechanical environment. We cultured hiPSC-CMs in a 96-well format on hyperelastic silicone membranes imitating their native mechanical environment, resulting in physiological responses to compound stimuli.We validated cell responses on the FLEXcyte 96, with a set of reference compounds covering a broad range of cellular targets, including ion channel modulators, adrenergic receptor modulators and kinase inhibitors. Acute (10 - 30 min) and chronic (up to 7 days) effects were investigated. Furthermore, the measurements were complemented with electromechanical models based on electrophysiological recordings of the used cell types.hiPSC-CMs were cultured on freely-swinging, ultra-thin and hyperelastic silicone membranes. The weight of the cell culture medium deflects the membranes downwards. Rhythmic contraction of the hiPSC-CMs resulted in dynamic deflection changes which were quantified by capacitive distance sensing. The cells were cultured for 7 days prior to compound addition. Acute measurements were conducted 10-30 minutes after compound addition in standard culture medium. For chronic treatment, compound-containing medium was replaced daily for up to 7 days. Electrophysiological properties of the employed cell types were recorded by automated patch-clamp (Patchliner) and the results were integrated into the electromechanical model of the system.Calcium channel agonist S Bay K8644 and beta-adrenergic stimulator isoproterenol induced significant positive inotropic responses without additional external stimulation. Kinase inhibitors displayed cardiotoxic effects on a functional level at low concentrations. The system-integrated analysis detected alterations in beating shape as well as frequency and arrhythmic events and we provide a quantitative measure of these.}, language = {en} } @incollection{KnottSofroniaGerressenetal.2014, author = {Knott, Thomas C. and Sofronia, Raluca E. and Gerressen, Marcus and Law, Yuen and Davidescu, Arjana and Savii, George G. and Gatzweiler, Karl-Heinz and Staat, Manfred and Kuhlen, Torsten W.}, title = {Preliminary bone sawing model for a virtual reality-based training simulator of bilateral sagittal split osteotomy}, series = {Biomedical simulation : 6th International Symposium, ISBMS 2014, Strasbourg, France, October 16-17, 2014 : proceedings (Lecture notes in computer science : vol. 8789)}, booktitle = {Biomedical simulation : 6th International Symposium, ISBMS 2014, Strasbourg, France, October 16-17, 2014 : proceedings (Lecture notes in computer science : vol. 8789)}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-12057-7 (Online)}, doi = {10.1007/978-3-319-12057-7_1}, pages = {1 -- 10}, year = {2014}, abstract = {Successful bone sawing requires a high level of skill and experience, which could be gained by the use of Virtual Reality-based simulators. A key aspect of these medical simulators is realistic force feedback. The aim of this paper is to model the bone sawing process in order to develop a valid training simulator for the bilateral sagittal split osteotomy, the most often applied corrective surgery in case of a malposition of the mandible. Bone samples from a human cadaveric mandible were tested using a designed experimental system. Image processing and statistical analysis were used for the selection of four models for the bone sawing process. The results revealed a polynomial dependency between the material removal rate and the applied force. Differences between the three segments of the osteotomy line and between the cortical and cancellous bone were highlighted.}, language = {en} } @article{KnobeGiesenPlateetal.2016, author = {Knobe, M. and Giesen, M. and Plate, S. and Gradl-Dietsch, G. and Buecking, B. and Eschbach, D. and Laack, Walter van and Pape, H.-C.}, title = {The Aachen mobility and balance index to measure physiological falls risk: a comparison with the Tinetti POMA scale}, series = {European Journal Of Trauma And Emergency Surgery}, volume = {42}, journal = {European Journal Of Trauma And Emergency Surgery}, number = {5}, publisher = {Springer}, address = {Berlin}, issn = {1863-9941}, doi = {10.1007/s00068-016-0693-2}, pages = {537 -- 545}, year = {2016}, abstract = {Purpose The most commonly used mobility assessments for screening risk of falls among older adults are rating scales such as the Tinetti performance oriented mobility assessment (POMA). However, its correlation with falls is not always predictable and disadvantages of the scale include difficulty to assess many of the items on a 3-point scale and poor specificity. The purpose of this study was to describe the ability of the new Aachen Mobility and Balance Index (AMBI) to discriminate between subjects with a fall history and subjects without such events in comparison to the Tinetti POMA Scale. Methods For this prospective cohort study, 24 participants in the study group and 10 in the control group were selected from a population of patients in our hospital who had met the stringent inclusion criteria. Both groups completed the Tinetti POMA Scale (gait and balance component) and the AMBI (tandem stance, tandem walk, ten-meter-walk-test, sit-to-stand with five repetitions, 360° turns, timed-up-and-go-test and measurement of the dominant hand grip strength). A history of falls and hospitalization in the past year were evaluated retrospectively. The relationships among the mobility tests were examined with Bland-Altmananalysis. Receiver-operated characteristics curves, sensitivity and specificity were calculated. Results The study showed a strong negative correlation between the AMBI (17 points max., highest fall risk) and Tinetti POMA Scale (28 points max., lowest fall risk; r = -0.78, p < 0.001) with an excellent discrimination between community-dwelling older people and a younger control group. However, there were no differences in any of the mobility and balance measurements between participants with and without a fall history with equal characteristics in test comparison (AMBI vs. Tinetti POMA Scale: AUC 0.570 vs. 0.598; p = 0.762). The Tinetti POMA Scale (cut-off <20 points) showed a sensitivity of 0.45 and a specificity of 0.69, the AMBI a sensitivity of 0.64 and a specificity of 0.46 (cut-off >5 points). Conclusion The AMBI comprises mobility and balance tasks with increasing difficulty as well as a measurement of the dominant hand-grip strength. Its ability to identify fallers was comparable to the Tinetti POMA Scale. However, both measurement sets showed shortcomings in discrimination between fallers and non-fallers based on a self-reported retrospective falls-status.}, language = {en} } @inproceedings{KloeserKohlKraftetal.2021, author = {Kl{\"o}ser, Lars and Kohl, Philipp and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {Multi-attribute relation extraction (MARE): simplifying the application of relation extraction}, series = {Proceedings of the 2nd International Conference on Deep Learning Theory and Applications - DeLTA}, booktitle = {Proceedings of the 2nd International Conference on Deep Learning Theory and Applications - DeLTA}, isbn = {978-989-758-526-5}, doi = {10.5220/0010559201480156}, pages = {148 -- 156}, year = {2021}, abstract = {Natural language understanding's relation extraction makes innovative and encouraging novel business concepts possible and facilitates new digitilized decision-making processes. Current approaches allow the extraction of relations with a fixed number of entities as attributes. Extracting relations with an arbitrary amount of attributes requires complex systems and costly relation-trigger annotations to assist these systems. We introduce multi-attribute relation extraction (MARE) as an assumption-less problem formulation with two approaches, facilitating an explicit mapping from business use cases to the data annotations. Avoiding elaborated annotation constraints simplifies the application of relation extraction approaches. The evaluation compares our models to current state-of-the-art event extraction and binary relation extraction methods. Our approaches show improvement compared to these on the extraction of general multi-attribute relations.}, language = {en} } @inproceedings{KloeserBuesgenKohletal.2023, author = {Kl{\"o}ser, Lars and B{\"u}sgen, Andr{\´e} and Kohl, Philipp and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {Explaining relation classification models with semantic extents}, series = {DeLTA 2023: Deep Learning Theory and Applications}, booktitle = {DeLTA 2023: Deep Learning Theory and Applications}, editor = {Conte, Donatello and Fred, Ana and Gusikhin, Oleg and Sansone, Carlo}, publisher = {Springer}, address = {Cham}, isbn = {978-3-031-39058-6 (Print)}, doi = {10.1007/978-3-031-39059-3_13}, pages = {189 -- 208}, year = {2023}, abstract = {In recent years, the development of large pretrained language models, such as BERT and GPT, significantly improved information extraction systems on various tasks, including relation classification. State-of-the-art systems are highly accurate on scientific benchmarks. A lack of explainability is currently a complicating factor in many real-world applications. Comprehensible systems are necessary to prevent biased, counterintuitive, or harmful decisions. We introduce semantic extents, a concept to analyze decision patterns for the relation classification task. Semantic extents are the most influential parts of texts concerning classification decisions. Our definition allows similar procedures to determine semantic extents for humans and models. We provide an annotation tool and a software framework to determine semantic extents for humans and models conveniently and reproducibly. Comparing both reveals that models tend to learn shortcut patterns from data. These patterns are hard to detect with current interpretability methods, such as input reductions. Our approach can help detect and eliminate spurious decision patterns during model development. Semantic extents can increase the reliability and security of natural language processing systems. Semantic extents are an essential step in enabling applications in critical areas like healthcare or finance. Moreover, our work opens new research directions for developing methods to explain deep learning models.}, language = {en} } @inproceedings{KloockSchoening2007, author = {Kloock, Joachim P. and Sch{\"o}ning, Michael Josef}, title = {Heavy metal detection with semiconductor devices based on PLD-prepared chalcogenide glass thin films}, series = {Armenian Journal of Physics}, booktitle = {Armenian Journal of Physics}, issn = {1829-1171}, pages = {95 -- 98}, year = {2007}, language = {en} } @inproceedings{KloockSchubertErmelenkoetal.2006, author = {Kloock, Joachim P. and Schubert, J. and Ermelenko, Y. and Vlasov, Y. G. and Bratov, A. and Sch{\"o}ning, Michael Josef}, title = {Thin-film sensors with chalcogenide glass materials - a general survey}, series = {Biochemical sensing utilisation of micro- and nanotechnologies : Warsaw, [23rd - 26th] November 2005 / ed. by M. Mascini ...}, booktitle = {Biochemical sensing utilisation of micro- and nanotechnologies : Warsaw, [23rd - 26th] November 2005 / ed. by M. Mascini ...}, address = {Warsaw}, pages = {92 -- 97}, year = {2006}, language = {en} } @article{KloockMourzinaErmolenkoetal.2004, author = {Kloock, Joachim P. and Mourzina, Y.G. and Ermolenko, Y. and Doll, T. and Schubert, J. and Sch{\"o}ning, Michael Josef}, title = {Inorganic thin-film sensor membranes with PLD-prepared chalcogenide glasses: Challenges and implementation}, series = {Sensors. 4 (2004), H. 10}, journal = {Sensors. 4 (2004), H. 10}, isbn = {1424-8220}, pages = {156 -- 162}, year = {2004}, language = {en} } @article{KloockMourzinaSchubertetal.2004, author = {Kloock, Joachim P. and Mourzina, Y. and Schubert, J. and Ermelenko, Y. and Sch{\"o}ning, Michael Josef}, title = {Pulsed laser deposition: A tool for fabricating thin-film microsensors}, series = {Biomedizinische Technik. 49 (2004), H. 2}, journal = {Biomedizinische Technik. 49 (2004), H. 2}, isbn = {0932-4666}, pages = {1032 -- 1033}, year = {2004}, language = {en} } @article{KloockMorenoBratovetal.2006, author = {Kloock, Joachim P. and Moreno, Lia and Bratov, A. and Huachupoma, S. and Xu, J. and Wagner, Torsten and Yoshinobu, T. and Ermolenko, Y. and Vlasov, Y. G. and Sch{\"o}ning, Michael Josef}, title = {PLD-prepared cadmium sensors based on chalcogenide glasses —ISFET, LAPS and \&\#956;ISE semiconductor structures}, series = {Sensors and Actuators B: Chemical. 118 (2006), H. 1-2}, journal = {Sensors and Actuators B: Chemical. 118 (2006), H. 1-2}, isbn = {0925-4005}, pages = {149 -- 155}, year = {2006}, language = {en} } @article{KleefeldReissel2011, author = {Kleefeld, A. and Reißel, Martin}, title = {The Levenberg-Marquardt method applied to a parameter estimation problem arising from electrical resistivity tomography}, series = {Applied Mathematics and Computation}, volume = {217}, journal = {Applied Mathematics and Computation}, number = {9}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {0096-3003}, pages = {4490 -- 4501}, year = {2011}, language = {en} } @article{KirchnerReisertPuetzetal.2012, author = {Kirchner, Patrick and Reisert, Steffen and P{\"u}tz, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100773}, pages = {859 -- 863}, year = {2012}, abstract = {Calorimetric gas sensors for monitoring the H₂O₂ concentration at elevated temperatures in industrial sterilisation processes have been presented in previous works. These sensors are built up in form of a differential set-up of a catalytically active and passive temperature-sensitive structure. Although, various types of catalytically active dispersions have been studied, the passivation layer has to be established and therefore, chemically as well as physically characterised. In the present work, fluorinated ethylene propylene (FEP), perfluoralkoxy (PFA) and epoxy-based SU-8 photoresist as temperature-stable polymeric materials have been investigated for sensor passivation in terms of their chemical inertness against H₂O₂, their hygroscopic properties as well as their morphology. The polymeric materials were deposited via spin-coating on the temperature-sensitive structure, wherein spin-coated FEP and PFA show slight agglomerates. However, they possess a low absorption of humidity due to their hydrophobic surface, whereas the SU-8 layer has a closed surface but shows a slightly higher absorption of water. All of them were inert against gaseous H₂O₂ during the characterisation in H₂O₂ atmosphere that demonstrates their suitability as passivation layer for calorimetric H₂O₂ gas sensors.}, language = {en} } @article{KirchnerOberlaenderSusoetal.2013, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Suso, Henri-Pierre and Rysstad, Gunnar and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Towards a wireless sensor system for real-time H2O2 monitoring in aseptic food processes}, series = {Physica status solidi (a)}, volume = {210}, journal = {Physica status solidi (a)}, number = {5}, publisher = {Wiley}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201200920}, pages = {877 -- 883}, year = {2013}, abstract = {A wireless sensor system based on the industrial ZigBee standard for low-rate wireless networking was developed that enables real-time monitoring of gaseous H2O2 during the package sterilization in aseptic food processes. The sensor system consists of a remote unit connected to a calorimetric gas sensor, which was already established in former works, and an external base unit connected to a laptop computer. The remote unit was built up by an XBee radio frequency (RF) module for data communication and a programmable system-on-chip controller to read out the sensor signal and process the sensor data, whereas the base unit is a second XBee RF module. For the rapid H2O2 detection on various locations inside the package that has to be sterilized, a novel read-out strategy of the calorimetric gas sensor was established, wherein the sensor response is measured within the short sterilization time and correlated with the present H2O2 concentration. In an exemplary measurement application in an aseptic filling machinery, the suitability of the new, wireless sensor system was demonstrated, wherein the influence of the gas velocity on the H2O2 distribution inside a package was determined and verified with microbiological tests.}, language = {en} } @article{KirchnerOberlaenderSucoetal.2013, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Suco, Henri-Pierre and Rysstad, Gunnar and Sch{\"o}ning, Michael Josef}, title = {Monitoring the microbicidal effectiveness of gaseous hydrogen peroxide in sterilisation processes by means of a calorimetric gas sensor}, series = {Food control}, volume = {31}, journal = {Food control}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0956-7135}, doi = {10.1016/j.foodcont.2012.11.048}, pages = {530 -- 538}, year = {2013}, abstract = {In the present work, a novel method for monitoring sterilisation processes with gaseous H2O2 in combination with heat activation by means of a specially designed calorimetric gas sensor was evaluated. Therefore, the sterilisation process was extensively studied by using test specimens inoculated with Bacillus atrophaeus spores in order to identify the most influencing process factors on its microbicidal effectiveness. Besides the contact time of the test specimens with gaseous H2O2 varied between 0.2 and 0.5 s, the present H2O2 concentration in a range from 0 to 8\% v/v (volume percent) had a strong influence on the microbicidal effectiveness, whereas the change of the vaporiser temperature, gas flow and humidity were almost negligible. Furthermore, a calorimetric H2O2 gas sensor was characterised in the sterilisation process with gaseous H2O2 in a wide range of parameter settings, wherein the measurement signal has shown a linear response against the H2O2 concentration with a sensitivity of 4.75 °C/(\% v/v). In a final step, a correlation model by matching the measurement signal of the gas sensor with the microbial inactivation kinetics was established that demonstrates its suitability as an efficient method for validating the microbicidal effectiveness of sterilisation processes with gaseous H2O2.}, language = {en} } @article{KirchnerOberlaenderFriedrichetal.2010, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Rysstad, G. and Berger, J. and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Realization of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry}, series = {Procedia Engineering. 5 (2010)}, journal = {Procedia Engineering. 5 (2010)}, isbn = {1877-7058}, pages = {264 -- 267}, year = {2010}, language = {en} } @article{KirchnerOberlaenderFriedrichetal.2011, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Berger, J{\"o}rg and Suso, Henri-Pierre and Kupyna, Andriy and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Optimisation and fabrication of a calorimetric gas sensor built up on a polyimide substrate for H2O2 monitoring}, series = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, journal = {Physica status solidi (a) : applications and material science. 208 (2011), H. 6}, publisher = {Wiley}, address = {Weinheim}, isbn = {1862-6319}, pages = {1235 -- 1240}, year = {2011}, language = {en} } @article{KirchnerOberlaenderFriedrichetal.2012, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Berger, J{\"o}rg and Rysstad, Gunnar and Sch{\"o}ning, Michael Josef and Keusgen, Michael}, title = {Realisation of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry}, series = {Sensors and Actuators B: Chemical}, volume = {170}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2011.01.032}, pages = {60 -- 66}, year = {2012}, abstract = {A calorimetric gas sensor is presented for the monitoring of vapour-phase H2O2 at elevated temperature during sterilisation processes in aseptic food industry. The sensor was built up on a flexible polyimide foil (thickness: 25 μm) that has been chosen due to its thermal stability and low thermal conductivity. The sensor set-up consists of two temperature-sensitive platinum thin-film resistances passivated by a layer of SU-8 photo resist and catalytically activated by manganese(IV) oxide. Instead of an active heating structure, the calorimetric sensor utilises the elevated temperature of the evaporated H2O2 aerosol. In an experimental test rig, the sensor has shown a sensitivity of 4.78 °C/(\%, v/v) in a H2O2 concentration range of 0\%, v/v to 8\%, v/v. Furthermore, the sensor possesses the same, unchanged sensor signal even at varied medium temperatures between 210 °C and 270 °C of the gas stream. At flow rates of the gas stream from 8 m3/h to 12 m3/h, the sensor has shown only a slightly reduced sensitivity at a low flow rate of 8 m3/h. The sensor characterisation demonstrates the suitability of the calorimetric gas sensor for monitoring the efficiency of industrial sterilisation processes.}, language = {en} } @article{KirchnerLiSpelthahnetal.2011, author = {Kirchner, Patrick and Li, Bin and Spelthahn, Heiko and Henkel, Hartmut and Schneider, Andreas and Friedrich, Peter and Kolstad, Jens and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Thin-film calorimetric H2O2 gas sensor for the validation of germicidal effectivity in aseptic filling processes}, series = {Sensors and Actuators B: Chemical. 154 (2011), H. 2}, journal = {Sensors and Actuators B: Chemical. 154 (2011), H. 2}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {1873-3077}, pages = {257 -- 263}, year = {2011}, language = {en} } @article{KirchnerLiSpelthahnetal.2009, author = {Kirchner, Patrick and Li, B. and Spelthahn, H. and Henkel, H. and Friedrich, P. and Kolstad, J. and Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Thin-film calorimetric H2O2 gas sensor for the validation of germicidal effectivity in aseptic filling processes}, series = {Procedia Chemistry. 1 (2009), H. 1}, journal = {Procedia Chemistry. 1 (2009), H. 1}, isbn = {1876-6196}, pages = {983 -- 986}, year = {2009}, language = {en} } @article{KhodaverdiWeberStreunetal.2006, author = {Khodaverdi, M. and Weber, S. and Streun, M. and Parl, C. and Ziemons, Karl}, title = {High resolution imaging with ClearPET™ Neuro - first animal images}, series = {2005 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, journal = {2005 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, isbn = {1082-3654}, pages = {1641 -- 1644}, year = {2006}, abstract = {The ClearPET™ Neuro is the first full ring scanner within the Crystal Clear Collaboration (CCC). It consists of 80 detector modules allocated to 20 cassettes. LSO and LuYAP:Ce crystals in phoswich configuration in combination with position sensitive photomultiplier tubes are used to achieve high sensitivity and realize the acquisition of the depth of interaction (DOI) information. The complete system has been tested concerning the mechanical and electronical stability and interplay. Moreover, suitable corrections have been implemented into the reconstruction procedure to ensure high image quality. We present first results which show the successful operation of the ClearPET™ Neuro for artefact free and high resolution small animal imaging. Based on these results during the past few months the ClearPET™ Neuro System has been modified in order to optimize the performance.}, language = {en} } @article{KhodaverdiPaulySchroderetal.2002, author = {Khodaverdi, M. and Pauly, F. and Schroder, G. and Ziemons, Karl and Sievering, R. and Halling, H.}, title = {Preliminary studies of a micro-CT for a combined small animal PET/CT scanner}, series = {2001 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, journal = {2001 IEEE Nuclear Science Symposium Conference Record, Vol. 3}, issn = {1082-3654}, pages = {1605 -- 1606}, year = {2002}, abstract = {We are developing an X-ray computed tomography (CT) system which will be combined with a high resolution animal PET system. This permits acquisition of both molecular and anatomical images in a single machine. In particular the CT will also be utilized for the quantification of the animal PET data by providing accurate data for attenuation correction. A first prototype has been built using a commercially available plane silicon diode detector. A cone-beam reconstruction provides the images using the Feldkamp algorithm. First measurements with this system have been performed on a mouse. It could be shown that the CT setup fulfils all demands for a high quality image of the skeleton of the mouse. It is also suited for soft tissue measurements. To improve contrast and resolution and to acquire the X-ray energy further development of the system, especially the use of semiconductor detectors and iterative reconstruction algorithms are planned.}, language = {en} } @article{KhodaverdiChaziioannouWeberetal.2004, author = {Khodaverdi, M. and Chaziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, U.}, title = {Investigation of different microCT scanner configurations by GEANT4 simulations}, series = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4}, journal = {2003 IEEE Nuclear Science Symposium Conference Record, Vol. 4}, issn = {1082-3654}, pages = {2989 -- 2993}, year = {2004}, abstract = {This study has been performed to design the combination of the new ClearPET TM (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal Positron Emission Tomography (PET) system, with a microComputed Tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.}, language = {en} } @article{KhodaverdiChatziioannouWeberetal.2005, author = {Khodaverdi, M. and Chatziioannou, A. F. and Weber, S. and Ziemons, Karl and Halling, H. and Pietrzyk, U.}, title = {Investigation of different MicroCT scanner configurations by GEANT4 simulations}, series = {IEEE Transactions on Nuclear Science}, volume = {52}, journal = {IEEE Transactions on Nuclear Science}, number = {1}, isbn = {0018-9499}, pages = {188 -- 192}, year = {2005}, abstract = {This study has been performed to design the combination of the new ClearPET (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal positron emission tomography (PET) system, with a micro-computed tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We will demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.}, language = {en} } @article{KhaydukovaZadorozhnayaKirsanovetal.2014, author = {Khaydukova, M. M. and Zadorozhnaya, O. A. and Kirsanov, D. O. and Iken, Heiko and Rolka, David and Sch{\"o}ning, Michael Josef and Babain, V. A. and Vlasov, Yu. G. and Legin, A. V.}, title = {Multivariate processing of atomic-force microscopy images for detection of the response of plasticized polymeric membranes}, series = {Russian journal of applied chemistry}, volume = {87}, journal = {Russian journal of applied chemistry}, number = {3}, publisher = {Springer}, address = {Dordrecht}, issn = {1608-3296 (E-Journal); 1070-4272 (Print)}, doi = {10.1134/S1070427214030112}, pages = {307 -- 314}, year = {2014}, abstract = {The possibility of using the atomic-force microscopy as a method for detection of the analytical signal from plasticized polymeric sensor membranes was analyzed. The surfaces of cadmium-selective membranes based on two polymeric matrices were examined. The digital images were processed with multivariate image analysis techniques. A correlation was found between the surface profile of an ion-selective membrane and the concentration of the ion in solution.}, language = {en} } @article{KeusgenJuengerKrestetal.2003, author = {Keusgen, Michael and J{\"u}nger, Martina and Krest, Ingo and Sch{\"o}ning, Michael Josef}, title = {Biosensoric detection of the cysteine sulphoxide alliin}, series = {Sensors and Actuators B. 95 (2003), H. 1-3}, journal = {Sensors and Actuators B. 95 (2003), H. 1-3}, isbn = {0925-4005}, pages = {297 -- 302}, year = {2003}, language = {en} } @article{KeusgenSchoening2004, author = {Keusgen, M. and Sch{\"o}ning, Michael Josef}, title = {Strategies for biosensoric detection of potential drugs in nature}, series = {Biomedizinische Technik. 49 (2004), H. 2}, journal = {Biomedizinische Technik. 49 (2004), H. 2}, isbn = {0932-4666}, pages = {1004 -- 1005}, year = {2004}, language = {en} } @article{KeusgenKloockKnobbeetal.2004, author = {Keusgen, M. and Kloock, Joachim P. and Knobbe, D.-T. and J{\"u}nger, M. and Krest, I. and Goldbach, M. and Klein, W. and Sch{\"o}ning, Michael Josef}, title = {Direct determination of cyanides by potentiometric biosensors}, series = {Sensors and Actuators B. 103 (2004), H. 1-2}, journal = {Sensors and Actuators B. 103 (2004), H. 1-2}, isbn = {0925-4005}, pages = {380 -- 385}, year = {2004}, language = {en} } @article{KeusgenJuengerSchoening2002, author = {Keusgen, M. and J{\"u}nger, M. and Sch{\"o}ning, Michael Josef}, title = {Biosensoric detection of the cysteine sulphoxide alliin}, series = {Book of abstracts / ed. by J. Saneistr.}, journal = {Book of abstracts / ed. by J. Saneistr.}, publisher = {Czech Technical University, Faculty of Electrical Engineering, Department of Measurement}, address = {Prague}, isbn = {80-01-02576-4}, pages = {1175 -- 1178}, year = {2002}, language = {en} } @article{KeusgenJuengerKrestetal.2003, author = {Keusgen, M. and J{\"u}nger, M. and Krest, I. and Sch{\"o}ning, Michael Josef}, title = {Development of a biosensor specific for cysteine sulfoxides}, series = {Biosensors \& Bioelectronics. 18 (2003), H. 5-6}, journal = {Biosensors \& Bioelectronics. 18 (2003), H. 5-6}, isbn = {0956-5663}, pages = {805 -- 812}, year = {2003}, language = {en} } @article{KetelhutKolditzGoelletal.2019, author = {Ketelhut, Maike and Kolditz, Melanie and G{\"o}ll, Fabian and Braunstein, Bjoern and Albracht, Kirsten and Abel, Dirk}, title = {Admittance control of an industrial robot during resistance training}, series = {IFAC-PapersOnLine}, volume = {52}, journal = {IFAC-PapersOnLine}, number = {19}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2019.12.102}, pages = {223 -- 228}, year = {2019}, abstract = {Neuromuscular strength training of the leg extensor muscles plays an important role in the rehabilitation and prevention of age and wealth related diseases. In this paper, we focus on the design and implementation of a Cartesian admittance control scheme for isotonic training, i.e. leg extension and flexion against a predefined weight. For preliminary testing and validation of the designed algorithm an experimental research and development platform consisting of an industrial robot and a force plate mounted at its end-effector has been used. Linear, diagonal and arbitrary two-dimensional motion trajectories with different weights for the leg extension and flexion part are applied. The proposed algorithm is easily adaptable to trajectories consisting of arbitrary six-dimensional poses and allows the implementation of individualized trajectories.}, language = {en} } @article{KetelhutGoellBraunsteinetal.2018, author = {Ketelhut, Maike and G{\"o}ll, Fabian and Braunstein, Bj{\"o}rn and Albracht, Kirsten and Abel, Dirk}, title = {Comparison of different training algorithms for the leg extension training with an industrial robot}, series = {Current Directions in Biomedical Engineering}, volume = {4}, journal = {Current Directions in Biomedical Engineering}, number = {1}, publisher = {De Gruyter}, address = {Berlin}, issn = {2364-5504}, doi = {10.1515/cdbme-2018-0005}, pages = {17 -- 20}, year = {2018}, abstract = {In the past, different training scenarios have been developed and implemented on robotic research platforms, but no systematic analysis and comparison have been done so far. This paper deals with the comparison of an isokinematic (motion with constant velocity) and an isotonic (motion against constant weight) training algorithm. Both algorithms are designed for a robotic research platform consisting of a 3D force plate and a high payload industrial robot, which allows leg extension training with arbitrary six-dimensional motion trajectories. In the isokinematic as well as the isotonic training algorithm, individual paths are defined i n C artesian s pace by sufficient s upport p oses. I n t he i sotonic t raining s cenario, the trajectory is adapted to the measured force as the robot should only move along the trajectory as long as the force applied by the user exceeds a minimum threshold. In the isotonic training scenario however, the robot's acceleration is a function of the force applied by the user. To validate these findings, a simulative experiment with a simple linear trajectory is performed. For this purpose, the same force path is applied in both training scenarios. The results illustrate that the algorithms differ in the force dependent trajectory adaption.}, language = {en} } @inproceedings{KetelhutGoellBraunsteinetal.2019, author = {Ketelhut, Maike and G{\"o}ll, Fabian and Braunstein, Bjoern and Albracht, Kirsten and Abel, Dirk}, title = {Iterative learning control of an industrial robot for neuromuscular training}, series = {2019 IEEE Conference on Control Technology and Applications}, booktitle = {2019 IEEE Conference on Control Technology and Applications}, publisher = {IEEE}, address = {New York}, isbn = {978-1-7281-2767-5 (ePub)}, doi = {10.1109/CCTA.2019.8920659}, pages = {7 Seiten}, year = {2019}, abstract = {Effective training requires high muscle forces potentially leading to training-induced injuries. Thus, continuous monitoring and controlling of the loadings applied to the musculoskeletal system along the motion trajectory is required. In this paper, a norm-optimal iterative learning control algorithm for the robot-assisted training is developed. The algorithm aims at minimizing the external knee joint moment, which is commonly used to quantify the loading of the medial compartment. To estimate the external knee joint moment, a musculoskeletal lower extremity model is implemented in OpenSim and coupled with a model of an industrial robot and a force plate mounted at its end-effector. The algorithm is tested in simulation for patients with varus, normal and valgus alignment of the knee. The results show that the algorithm is able to minimize the external knee joint moment in all three cases and converges after less than seven iterations.}, language = {en} } @article{KetelhutBrueggeGoelletal.2020, author = {Ketelhut, Maike and Br{\"u}gge, G. M. and G{\"o}ll, Fabian and Braunstein, Bjoern and Albracht, Kirsten and Abel, Dirk}, title = {Adaptive iterative learning control of an industrial robot during neuromuscular training}, series = {IFAC PapersOnLine}, volume = {53}, journal = {IFAC PapersOnLine}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {2405-8963}, doi = {10.1016/j.ifacol.2020.12.741}, pages = {16468 -- 16475}, year = {2020}, abstract = {To prevent the reduction of muscle mass and loss of strength coming along with the human aging process, regular training with e.g. a leg press is suitable. However, the risk of training-induced injuries requires the continuous monitoring and controlling of the forces applied to the musculoskeletal system as well as the velocity along the motion trajectory and the range of motion. In this paper, an adaptive norm-optimal iterative learning control algorithm to minimize the knee joint loadings during the leg extension training with an industrial robot is proposed. The response of the algorithm is tested in simulation for patients with varus, normal and valgus alignment of the knee and compared to the results of a higher-order iterative learning control algorithm, a robust iterative learning control and a recently proposed conventional norm-optimal iterative learning control algorithm. Although significant improvements in performance are made compared to the conventional norm-optimal iterative learning control algorithm with a small learning factor, for the developed approach as well as the robust iterative learning control algorithm small steady state errors occur.}, language = {en} } @article{KaulKoshkaryevArtmannetal.2008, author = {Kaul, D. K. and Koshkaryev, A. and Artmann, Gerhard and Barshtein, G. and Yedgar, S.}, title = {Additive effect of red blood cell rigidity and adherence to endothelial cells in inducing vascular resistance}, series = {American Journal of Physiology : Heart and Circulation Physiology . 295 (2008), H. 4}, volume = {295}, journal = {American Journal of Physiology : Heart and Circulation Physiology . 295 (2008), H. 4}, number = {4}, issn = {1522-1539}, pages = {H1788 -- H1793}, year = {2008}, language = {en} } @article{KatzPoghossianSchoening2017, author = {Katz, Evgeny and Poghossian, Arshak and Sch{\"o}ning, Michael Josef}, title = {Enzyme-based logic gates and circuits - analytical applications and interfacing with electronics}, series = {Analytical and Bioanalytical Chemistry}, volume = {409}, journal = {Analytical and Bioanalytical Chemistry}, publisher = {Springer}, address = {Berlin}, issn = {1618-2650}, doi = {10.1007/s00216-016-0079-7}, pages = {81 -- 94}, year = {2017}, abstract = {The paper is an overview of enzyme-based logic gates and their short circuits, with specific examples of Boolean AND and OR gates, and concatenated logic gates composed of multi-step enzyme-biocatalyzed reactions. Noise formation in the biocatalytic reactions and its decrease by adding a "filter" system, converting convex to sigmoid response function, are discussed. Despite the fact that the enzyme-based logic gates are primarily considered as components of future biomolecular computing systems, their biosensing applications are promising for immediate practical use. Analytical use of the enzyme logic systems in biomedical and forensic applications is discussed and exemplified with the logic analysis of biomarkers of various injuries, e.g., liver injury, and with analysis of biomarkers characteristic of different ethnicity found in blood samples on a crime scene. Interfacing of enzyme logic systems with modified electrodes and semiconductor devices is discussed, giving particular attention to the interfaces functionalized with signal-responsive materials. Future perspectives in the design of the biomolecular logic systems and their applications are discussed in the conclusion.}, language = {en} } @article{KassabHanPoghossianetal.2004, author = {Kassab, T. and Han, Y. and Poghossian, Arshak and Ingebrandt, S. and Offenh{\"a}usser, A. and Sch{\"o}ning, Michael Josef}, title = {Detection of layerby-layer adsorbed polyelectrolytes by means of field-effect based capacitive EIS structures}, series = {Biomedizinische Technik. 49 (2004), H. 2}, journal = {Biomedizinische Technik. 49 (2004), H. 2}, isbn = {0932-4666}, pages = {1034 -- 1035}, year = {2004}, language = {en} } @article{KarschuckPoghossianSeretal.2024, author = {Karschuck, Tobias and Poghossian, Arshak and Ser, Joey and Tsokolakyan, Astghik and Achtsnicht, Stefan and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Capacitive model of enzyme-modified field-effect biosensors: Impact of enzyme coverage}, series = {Sensors and Actuators B: Chemical}, volume = {408}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005 (Print)}, doi = {10.1016/j.snb.2024.135530}, pages = {12 Seiten}, year = {2024}, abstract = {Electrolyte-insulator-semiconductor capacitors (EISCAP) belong to field-effect sensors having an attractive transducer architecture for constructing various biochemical sensors. In this study, a capacitive model of enzyme-modified EISCAPs has been developed and the impact of the surface coverage of immobilized enzymes on its capacitance-voltage and constant-capacitance characteristics was studied theoretically and experimentally. The used multicell arrangement enables a multiplexed electrochemical characterization of up to sixteen EISCAPs. Different enzyme coverages have been achieved by means of parallel electrical connection of bare and enzyme-covered single EISCAPs in diverse combinations. As predicted by the model, with increasing the enzyme coverage, both the shift of capacitance-voltage curves and the amplitude of the constant-capacitance signal increase, resulting in an enhancement of analyte sensitivity of the EISCAP biosensor. In addition, the capability of the multicell arrangement with multi-enzyme covered EISCAPs for sequentially detecting multianalytes (penicillin and urea) utilizing the enzymes penicillinase and urease has been experimentally demonstrated and discussed.}, language = {en} } @article{KarschuckFilipovBollellaetal.2019, author = {Karschuck, T. L. and Filipov, Y. and Bollella, P. and Sch{\"o}ning, Michael Josef and Katz, E.}, title = {Not-XOR (NXOR) logic gate based on an enzyme-catalyzed reaction}, series = {International Journal of Unconventional Computing}, volume = {14}, journal = {International Journal of Unconventional Computing}, number = {3-4}, publisher = {Old City Publishing}, address = {Philadelphia}, issn = {1548-7199}, pages = {235 -- 242}, year = {2019}, abstract = {Enzyme-catalyzed reactions have been designed to mimic various Boolean logic gates in the general framework of unconventional biomolecular computing. While some of the logic gates, particularly OR, AND, are easy to realize with biocatalytic reactions and have been reported in numerous publications, some other, like NXOR, are very challenging and have not been realized yet with enzyme reactions. The paper reports on a novel approach to mimicking the NXOR logic gate using the bell-shaped enzyme activity dependent on pH values. Shifting pH from the optimum value to the acidic or basic values by using acid or base inputs (meaning 1,0 and 0,1 inputs) inhibits the enzyme reaction, while keeping the optimum pH (assuming 0,0 and 1,1 input combinations) preserves a high enzyme activity. The challenging part of the present approach is the selection of an enzyme with a well-demonstrated bell-shape activity dependence on the pH value. While many enzymes can satisfy this condition, we selected pyrroloquinoline quinone (PQQ)-dependent glucose dehydrogenase as this enzyme has the optimum pH center-located on the pH scale allowing the enzyme activity change by the acidic and basic pH shift from the optimum value corresponding to the highest activity. The present NXOR gate is added to the biomolecular "toolbox" as a new example of Boolean logic gates based on enzyme reactions.}, language = {en} } @article{KarnatakKantzBialonski2017, author = {Karnatak, Rajat and Kantz, Holger and Bialonski, Stephan}, title = {Early warning signal for interior crises in excitable systems}, series = {Physical Review E}, volume = {96}, journal = {Physical Review E}, number = {4}, issn = {2470-0053}, doi = {10.1103/PhysRevE.96.042211}, pages = {042211}, year = {2017}, language = {en} } @article{KaramanidisAlbrachtBraunsteinetal.2011, author = {Karamanidis, Kiros and Albracht, Kirsten and Braunstein, Bjoern and Catala, Maria Moreno and Goldmann, Jan-Peter and Br{\"u}ggemann, Gert-Peter}, title = {Lower leg musculoskeletal geometry and sprint performance}, series = {Gait and Posture}, volume = {34}, journal = {Gait and Posture}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0966-6362}, doi = {10.1016/j.gaitpost.2011.03.009}, pages = {138 -- 141}, year = {2011}, abstract = {The purpose of this study was to investigate whether sprint performance is related to lower leg musculoskeletal geometry within a homogeneous group of highly trained 100-m sprinters. Using a cluster analysis, eighteen male sprinters were divided into two groups based on their personal best (fast: N = 11, 10.30 ± 0.07 s; slow: N = 7, 10.70 ± 0.08 s). Calf muscular fascicle arrangement and Achilles tendon moment arms (calculated by the gradient of tendon excursion versus ankle joint angle) were analyzed for each athlete using ultrasonography. Achilles tendon moment arm, foot and ankle skeletal geometry, fascicle arrangement as well as the ratio of fascicle length to Achilles tendon moment arm showed no significant (p > 0.05) correlation with sprint performance, nor were there any differences in the analyzed musculoskeletal parameters between the fast and slow sprinter group. Our findings provide evidence that differences in sprint ability in world-class athletes are not a result of differences in the geometrical design of the lower leg even when considering both skeletal and muscular components.}, language = {en} } @article{KaminskyWeberSimonsetal.2005, author = {Kaminsky, Randolph and Weber, Hans-Joachim and Simons, Antoine and Kallweit, Stephan and Kramm, K. and Verdonck, Pascale}, title = {Comparison of the flow downstream two prototypes of a new monoleaflet artificial aortic heart valve by means of PIV visualization}, series = {Computer methods in biomechanics and biomedical engineering. 8 (2005), H. 4, Suppl. 1}, journal = {Computer methods in biomechanics and biomedical engineering. 8 (2005), H. 4, Suppl. 1}, isbn = {1476-8259}, pages = {159 -- 160}, year = {2005}, language = {en} } @article{KaminskySimonsGatzweileretal.2005, author = {Kaminsky, Randolph and Simons, Antoine and Gatzweiler, Karl-Heinz and Weber, Hans-Joachim}, title = {Flow visualization by means of PIV of an artificial aortic heart valve fixed into a mock aorta}, series = {Acta Mechanica Slovaka 2-A. 9 (2005)}, journal = {Acta Mechanica Slovaka 2-A. 9 (2005)}, pages = {343 -- 348}, year = {2005}, language = {en} } @book{KaminskyKallweitWeberetal.2006, author = {Kaminsky, Radoslav and Kallweit, Stephan and Weber, Hans-Joachim and Simons, Antoine and Verdonck, Pascal}, title = {Stereo high speed PIV measurements behind two different artificial heart valves}, pages = {9 S. : Ill., graph. Darst.}, year = {2006}, language = {en} } @article{KaminskyKallweitWeberetal.2006, author = {Kaminsky, Radoslav and Kallweit, Stephan and Weber, Hans-Joachim and Simons, Antoine and Kramm, K. and Jazwik, K. and Moll, J. and Verdonck, P.}, title = {3D high speed piv assessment of a new aortic heart valve prototype}, series = {Journal of biomechanics. 39 (2006), H. Supplement 1}, journal = {Journal of biomechanics. 39 (2006), H. Supplement 1}, publisher = {-}, isbn = {0021-9290}, pages = {S304 -- S305}, year = {2006}, language = {en} } @article{KaminskyKallweitWeberetal.2007, author = {Kaminsky, Radoslav and Kallweit, Stephan and Weber, Hans-Joachim and Claessens, Tom and Jozwik, Krzystof and Verdonck, Pascal}, title = {Flow visualization through two types of aortic prosthetic heart valves using stereoscopic high-speed particle image velocimetry}, series = {Artificial organs. 31 (2007), H. 12}, journal = {Artificial organs. 31 (2007), H. 12}, isbn = {1525-1594}, pages = {869 -- 879}, year = {2007}, language = {en} } @article{KaminskyDumontWeberetal.2007, author = {Kaminsky, Radoslav and Dumont, K. and Weber, Hans-Joachim and Schroll, M. and Verdonck, P.}, title = {PIV validation of blood-heart valve leaflet interaction modelling}, series = {The International journal of artificial organs. 30 (2007), H. 7}, journal = {The International journal of artificial organs. 30 (2007), H. 7}, publisher = {-}, pages = {640 -- 648}, year = {2007}, language = {en} } @inproceedings{KahmannUschokWegmannetal.2018, author = {Kahmann, Stephanie Lucina and Uschok, Stephan and Wegmann, Kilian and M{\"u}ller, Lars-P. and Staat, Manfred}, title = {Biomechanical multibody model with refined kinematics of the elbow}, series = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, booktitle = {6th European Conference on Computational Mechanics (ECCM 6), 7th European Conference on Computational Fluid Dynamics (ECFD 7), 11-15 June 2018, Glasgow, UK}, pages = {11 Seiten}, year = {2018}, abstract = {The overall objective of this study is to develop a new external fixator, which closely maps the native kinematics of the elbow to decrease the joint force resulting in reduced rehabilitation time and pain. An experimental setup was designed to determine the native kinematics of the elbow during flexion of cadaveric arms. As a preliminary study, data from literature was used to modify a published biomechanical model for the calculation of the joint and muscle forces. They were compared to the original model and the effect of the kinematic refinement was evaluated. Furthermore, the obtained muscle forces were determined in order to apply them in the experimental setup. The joint forces in the modified model differed slightly from the forces in the original model. The muscle force curves changed particularly for small flexion angles but their magnitude for larger angles was consistent.}, language = {en} } @inproceedings{KahmannHacklWegmannetal.2016, author = {Kahmann, Stephanie and Hackl, Michael and Wegmann, Kilian and M{\"u}ller, Lars-Peter and Staat, Manfred}, title = {Impact of a proximal radial shortening osteotomy on the distribution of forces and the stability of the elbow}, series = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, booktitle = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, editor = {Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, doi = {10.17185/duepublico/40821}, pages = {7 -- 8}, year = {2016}, abstract = {The human arm consists of the humerus (upper arm), the medial ulna and the lateral radius (forearm). The joint between the humerus and the ulna is called humeroulnar joint and the joint between the humerus and the radius is called humeroradial joint. Lateral and medial collateral ligaments stabilize the elbow. Statistically, 2.5 out of 10,000 people suffer from radial head fractures [1]. In these fractures the cartilage is often affected. Caused by the injured cartilage, degenerative diseases like posttraumatic arthrosis may occur. The resulting pain and reduced range of motion have an impact on the patient's quality of life. Until now, there has not been a treatment which allows typical loads in daily life activities and offers good long-term results. A new surgical approach was developed with the motivation to reduce the progress of the posttraumatic arthrosis. Here, the radius is shortened by 3 mm in the proximal part [2]. By this means, the load of the radius is intended to be reduced due to a load shift to the ulna. Since the radius is the most important stabilizer of the elbow it has to be confirmed that the stability is not affected. In the first test (Fig. 1 left), pressure distributions within the humeroulnar and humeroradial joints a native and a shortened radius were measured using resistive pressure sensors (I5076 and I5027, Tekscan, USA). The humerus was loaded axially in a tension testing machine (Z010, Zwick Roell, Germany) in 50 N steps up to 400 N. From the humerus the load is transmitted through both the radius and the ulna into the hand which is fixed on the ground. In the second test (Fig. 1 right), the joint stability was investigated using a digital image correlation system to measure the displacement of the ulna. Here, the humerus is fixed with a desired flexion angle and the unconstrained forearm lies on the ground. A rope connects the load actuator with a hook fixed in the ulna. A guide roller is used so that the rope pulls the ulna horizontally when a tensile load is applied. This creates a moment about the elbow joint with a maximum value of 7.5 Nm. Measurements were performed with varying flexion angles (0°, 30°, 60°, 90°, 120°). For both tests and each measurement, seven specimens were used. Student's t-test was employed to determine whether the mean values of the measurements in native specimen and operated specimens differ significantly.}, language = {en} }