Auflistung nach Schlagwort "600 - Technik, Medizin, angewandte Wissenschaften"

Gerade angezeigt 1 - 20 von 355

2D-3D-Modellerzeuger
30% oder 80% Eigenverbrauch?
(AZ Medien AG, 06/2019) Hall, Monika; Bittel, Raphael
Infolge der steigenden dezentralen Stromerzeugung wird der Eigenverbrauch immer wichtiger. Die Eigenverbrauchsrate sollte daher bestimmt werden. Je nach zeitlicher Auflösung der Gebäudebilanzierung kommt man jedoch zu unterschiedlichen Ergebnissen. Welche Zeitschritte sind für die Praxis sinnvoll? Die Ergebnisse zeigen, dass zur Bestimmung der Eigenverbrauchsrate und dem Autarkiegrad eine zeitliche Auflösung der Daten von einer Stunde ausreichend ist. Der Fehler ist mit dieser Auflösung gegen über 1 min Werten nicht sehr gross. Wird eine Batterie eingesetzt, spielt die Auflösung von 1, 15 oder 60 min keine Rolle mehr.
01B - Beitrag in Magazin oder Zeitung
3D printed microfluidic modules. Passive mixers and cells encapsulation in alginate
(De Gruyter, 02.09.2022) Dalcanale, Federico; Caj, Michaela; Schuler, Felix; Ganeshanathan, Kireedan; Suter-Dick, Laura
Passive mixers and droplet generation microfluidic chip modules were designed and manufactured using a commercial SLA 3D-printer. The mixing modules were designed specifically for 3D-printing and evaluated using FEM modeling. The co-flow droplet generator was used for cancer cells encapsulation and drug potency evaluation.
01A - Beitrag in wissenschaftlicher Zeitschrift
3D-printed LEGO®-inspired titanium scaffolds for patient-specific regenerative medicine
(Elsevier, 2023) Lee, Seunghun S.; Du, Xiaoyu; Smit, Thijs; Bissacco, Elisa G.; Seiler, Daniel; de Wild, Michael; Ferguson, Stephen J.
Despite the recent advances in 3D-printing, it is often difficult to fabricate implants that optimally fit a defect size or shape. There are some approaches to resolve this issue, such as patient-specific implant/scaffold designs based on CT images of the patients, however, this process is labor-intensive and costly. Especially in developing countries, affordable treatment options are required, while still not excluding these patient groups from potential material and manufacturing advances. Here, a selective laser melting (SLM) 3D-printing strategy was used to fabricate a hierarchical, LEGO®-inspired Assemblable Titanium Scaffold (ATS) system, which can be manually assembled in any shape or size with ease. A surgeon can quickly create a scaffold that would fit to the defect right before the implantation during the surgery. Additionally, the direct inclusion of micro- and macroporous structures via 3D-printing, as well as a double acid-etched surface treatment (ST) in the ATS, ensure biocompatibility, sufficient nutrient flow, cell migration and enhanced osteogenesis. Three different structures were designed (non-porous:NP, semi-porous:SP, ultra-porous:UP), 3D-printed with the SLM technique and then surface treated for the ST groups. After analyzing characteristics of the ATS such as printing quality, surface roughness and interconnected porosity, mechanical testing and finite element analysis (FEA) demonstrated that individual and stacked ATS have sufficient mechanical properties to withstand loading in a physiological system. All ATS showed high cell viability, and the SP and UP groups demonstrated enhanced cell proliferation rates compared to the NP group. Furthermore, we also verified that cells were well-attached and spread on the porous structures and successful cell migration between the ATS units was seen in the case of assemblies. The UP and SP groups exhibited higher calcium deposition and RT-qPCR proved higher osteogenic gene expression compared to NP group. Finally, we demonstrate a number of possible medical applications that reveal the potential of the ATS through assembly. © 2023 The Authors
01A - Beitrag in wissenschaftlicher Zeitschrift
4D4SBB
4uComputing
A baseline wander tracking system for artifact rejection in long-term electrocardiography
(IEEE, 2016) Niederhauser, Thomas; Marisa, Thanks; Kohler, Lukas; Haeberlin, Andreas; Wildhaber, Reto; Abächerli, Roger; Goette, Josef; Jacomet, Marcel; Vogel, Rolf
Long-term electrocardiogram (ECG) signals might suffer from relevant baseline disturbances during physical activity. Motion artifacts in particular are more pronounced with dry surface or esophageal electrodes which are dedicated to prolonged ECG recording. In this paper we present a method called baseline wander tracking (BWT) that tracks and rejects strong baseline disturbances and avoids concurrent saturation of the analog front-end. The proposed algorithm shifts the baseline level of the ECG signal to the middle of the dynamic input range. Due to the fast offset shifts, that produce much steeper signal portions than the normal ECG waves, the true ECG signal can be reconstructed offline and filtered using computationally intensive algorithms. Based on Monte Carlo simulations we observed reconstruction errors mainly caused by the non-linearity inaccuracies of the DAC. However, the signal to error ratio of the BWT is higher compared to an analog front-end featuring a dynamic input ranges above 15 mV if a synthetic ECG signal was used. The BWT is additionally able to suppress (electrode) offset potentials without introducing long transients. Due to its structural simplicity, memory efficiency and the DC coupling capability, the BWT is dedicated to high integration required in long-term and low-power ECG recording systems.
01A - Beitrag in wissenschaftlicher Zeitschrift
A change of theme. The role of generalization in thematic mapping
(MDPI, 2020) Raposo, Paulo; Touya, Guillaume; Bereuter, Pia
Cartographic generalization research has focused almost exclusively in recent years on topographic mapping, and has thereby gained an incorrect reputation for having to do only with reference or positional data. The generalization research community needs to broaden its scope to include thematic cartography and geovisualization. Generalization is not new to these areas of cartography, and has in fact always been involved in thematic geographic visualization, despite rarely being acknowledged. We illustrate this involvement with several examples of famous, public-audience thematic maps, noting the generalization procedures involved in drawing each, both across their basemap and thematic layers. We also consider, for each map example we note, which generalization operators were crucial to the formation of the map’s thematic message. The many incremental gains made by the cartographic generalization research community while treating reference data can be brought to bear on thematic cartography in the same way they were used implicitly on the well-known thematic maps we highlight here as examples.
01A - Beitrag in wissenschaftlicher Zeitschrift
A Change of theme. The role of generalization in thematic mapping
(MDPI, 04.06.2020) Raposo, Paulo; Touya, Guillaume; Bereuter, Pia
Cartographic generalization research has focused almost exclusively in recent years on topographic mapping, and has thereby gained an incorrect reputation for having to do only with reference or positional data. The generalization research community needs to broaden its scope to include thematic cartography and geovisualization. Generalization is not new to these areas of cartography, and has in fact always been involved in thematic geographic visualization, despite rarely being acknowledged. We illustrate this involvement with several examples of famous, public-audience thematic maps, noting the generalization procedures involved in drawing each, both across their basemap and thematic layers. We also consider, for each map example we note, which generalization operators were crucial to the formation of the map’s thematic message. The many incremental gains made by the cartographic generalization research community while treating reference data can be brought to bear on thematic cartography in the same way they were used implicitly on the well-known thematic maps we highlight here as examples.
01A - Beitrag in wissenschaftlicher Zeitschrift
A graphical simulation software for instruction in cardiovascular mechanics physiology
(2011) Wildhaber, Reto; Verrey, François; Wenger, Roland H
Background Computer supported, interactive e-learning systems are widely used in the teaching of physiology. However, the currently available complimentary software tools in the field of the physiology of cardiovascular mechanics have not yet been adapted to the latest systems software. Therefore, a simple-to-use replacement for undergraduate and graduate students' education was needed, including an up-to-date graphical software that is validated and field-tested.
01A - Beitrag in wissenschaftlicher Zeitschrift
A novel route to molecular self-assembly. Self-intermixed monolayer phases
(Wiley, 18.10.2002) de Wild, Michael; Berner, Simon; Suzuki, Hitoshi; Yanagi, Hisao; Schlettwein, Derck; Ivan, Stanislav; Baratoff, Alexis; Guentherodt, Hans-Joachim; Jung, Thomas A.
The stars and stripes: A novel route to highly perfect molecular self-assembly is presented. Depending on the relative surface (Ag(111)) coverage of the two species, subphthalocyanine and C60 (green and yellow in the colored STM image) on an surface, well-ordered intermixed monolayers consisting of 1D chains with 1 nm width or 2D hexagonal patterns are formed. The structural parameters and schematic binary "phase diagram" of this system are deduced from detailed room-temperature STM studies. The most important underlying interactions and the relevant properties of the molecules are discussed qualitatively.
01A - Beitrag in wissenschaftlicher Zeitschrift
A survey of practice patterns for adaptive particle therapy for interfractional changes
(Elsevier, 04/2023) Trnkova, Petra; Zhang, Ye; Toshito, Toshiyuki; Heijmen, Ben; Richter, Christian; Aznar, Marianne C.; Albertini, Francesca; Bolsi, Alessandra; Daartz, Juliane; Knopf, Antje; Bertholet, Jenny
01A - Beitrag in wissenschaftlicher Zeitschrift
Abschlussbericht über die Messungen des Gleichgewichtsfaktors zwischen Radon und seinen kurzlebigen Folgeprodukten in Objekten des VBS. Eine Zusammenstellung und Auswertung von Kurz- und Langzeitmessungen der potenziellen Alphaenergiekonzentration sowie Messungen der Aerosolkonzentration
(Institut Nachhaltigkeit und Energie am Bau, Hochschule für Architektur, Bau und Geomatik FHNW, 28.02.2024) Grapentin, Raphael
In den Jahren von 2020 bis 2023 wurden in diversen ober- und unterirdischen Objekten des VBS Messungen durchgeführt, bei welchen die Radonkonzentration und der Gleichgewichtsfaktor simultan gemessen wurden. Neben 107 Kurzzeitmessungen in 43 Objekten wurden in drei Objekten insgesamt neun Langzeitmessungen durchgeführt. Zusätzlich wurden in einem Objekt drei Messungen der Radonkonzentration, des Gleichgewichtsfaktors und der Aerosolkonzentration durchgeführt. Über alle Kurzzeitmessungen lag der Mittelwert der Radonkonzentration bei 721 Bq/m³ und des Gleichgewichtsfaktors bei 0.29, die Langzeitmessungen zeigten Radonkonzentrationen zwischen 0 bis maximal 14000 Bq/m³ und Gleichgewichtsfaktoren zwischen 0.01 und 0.6. Dabei zeigt sich, dass die mechanische Belüftung eines Objektes einen starken Einfluss auf alle Messgrössen hat. Der Zusammenhang zwischen Aerosolkonzentration und Gleichgewichtsfaktor konnte nicht abschliessend geklärt werden. Aufgrund dieser Messwerte wird empfohlen, dass für eine präzise Dosisabschätzung eine Messung des Gleichgewichtsfaktors durchzuführen ist.
05 - Forschungs- oder Arbeitsbericht
Absorption and metabolism of the natural sweeteners erythritol and xylitol in humans. A dose-ranging study
(MDPI, 30.08.2022) Wölnerhanssen, Bettina K.; Meyer-Gerspach, Anne Christin; Bordier, Valentine; Teysseire, Valentine; Senner, Frank; Schlotterbeck, Götz; Drewe, Jürgen; Beglinger, Christoph
The natural sweeteners erythritol and xylitol might be helpful to reduce sugar consumption and therefore prevent obesity and diabetes. The aim of the present study was to determine the absorption and metabolization into erythronate of different concentrations of erythritol and xylitol. Seventeen healthy lean participants received intragastric solutions of 10, 25, or 50 g erythritol or 7, 17, or 35 g xylitol on three study days in a randomized order. The study was double blinded with respect to the doses administered. We assessed plasma concentrations of erythritol, xylitol, and erythronate at fixed time intervals after administration with gas chromatography-mass spectrometry. We found: (i) a dose-dependent and saturable absorption of erythritol, (ii) a very low absorption of xylitol, (iii) a dose-dependent metabolization of erythritol into erythronate, and (iv) no metabolization of xylitol into erythronate. The implications of the metabolization of erythritol into erythronate for human health remain to be determined and more research in this area is needed.
01A - Beitrag in wissenschaftlicher Zeitschrift
Accurate visual localization in outdoor and indoor environments exploiting 3D image spaces as spatial reference
(International Society for Photogrammetry and Remote Sensing, 2018) Rettenmund, Daniel; Fehr, Markus; Cavegn, Stefan; Nebiker, Stephan
In this paper, we present a method for visual localization and pose estimation based on 3D image spaces. The method works in indoor and outdoor environments and does not require the presence of control points or markers. The method is evaluated with different sensors in an outdoor and an indoor test field. The results of our research show the viability of single image localization with absolute position accuracies at the decimetre level for outdoor environments and 5 cm or better for indoor environments. However, the evaluation also revealed a number of limitations of single image visual localization in real-world environments. Some of them could be addressed by an alternative AR-based localization approach, which we also present and compare in this paper. We then discuss the strengths and weaknesses of the two approaches and show possibilities for combining them to obtain accurate and robust visual localization in an absolute coordinate frame.
04B - Beitrag Konferenzschrift
Advancing algorithmic drug product development. Recommendations for machine learning approaches in drug formulation
(Elsevier, 2023) Murray, Jack D.; Lange, Justus J.; Bennett-Lenane, Harriet; Holm, René; Kuentz, Martin; O'Dwyer, Patrick J.; Griffin, Brendan T.
Artificial intelligence is a rapidly expanding area of research, with the disruptive potential to transform traditional approaches in the pharmaceutical industry, from drug discovery and development to clinical practice. Machine learning, a subfield of artificial intelligence, has fundamentally transformed in silico modelling and has the capacity to streamline clinical translation. This paper reviews data-driven modelling methodologies with a focus on drug formulation development. Despite recent advances, there is limited modelling guidance specific to drug product development and a trend towards suboptimal modelling practices, resulting in models that may not give reliable predictions in practice. There is an overwhelming focus on benchtop experimental outcomes obtained for a specific modelling aim, leaving the capabilities of data scraping or the use of combined modelling approaches yet to be fully explored. Moreover, the preference for high accuracy can lead to a reliance on black box methods over interpretable models. This further limits the widespread adoption of machine learning as black boxes yield models that cannot be easily understood for the purposes of enhancing product performance. In this review, recommendations for conducting machine learning research for drug product development to ensure trustworthiness, transparency, and reliability of the models produced are presented. Finally, possible future directions on how research in this area might develop are discussed to aim for models that provide useful and robust guidance to formulators. © 2023
01A - Beitrag in wissenschaftlicher Zeitschrift
AI-based 3D detection of parked vehicles on a mobile mapping platform using edge computing
(2022) Meyer, Jonas; Blaser, Stefan; Nebiker, Stephan
In this paper we present an edge-based hardware and software framework for the 3D detection and mapping of parked vehicles on a mobile mapping platform for the use case of on-street parking statistics. First, we investigate different point cloud-based 3D object detection methods on our extremely dense and noisy depth maps obtained from low-cost RGB-D sensors to find a suitable object detector and determine the optimal preparation of our data. We then retrain the chosen object detector to detect all types of vehicles, rather than standard cars only. Finally, we design and develop a software framework integrating the newly trained object detector. By repeating the parking statistics of our previous work (Nebiker et al., 2021), our software is tested regarding the detection accuracy. With our edge-based framework, we achieve a precision and recall of 100% and 98% respectively on any parking configuration and vehicle type, outperforming all other known work on on-street parking statistics. Furthermore, our software is evaluated in terms of processing speed and volume of generated data. While the processing speed reaches only 1.9 frames per second due to limited computing resources, the amount of data generated is just 0.25 KB per frame.
04B - Beitrag Konferenzschrift
Aktivitätenbasierte Verkehrsmodelle
(Bundesamt für Strassen, 12.12.2021) Vitins, Basil; Erath, Alexander; Fellendorf, Martin; Arendt, Michael
05 - Forschungs- oder Arbeitsbericht
Algorithm for real-time analysis of intracoronary electrocardiogram
(Frontiers, 07.09.2022) Bigler, Marius Reto; Kieninger-Gräfitsch, Andrea; Waldmann, Frédéric; Seiler, Christian; Wildhaber, Reto
Since its first implementation in 1985, intracoronary (ic) electrocardiogram (ECG) has shown ample evidence for its diagnostic value given the higher sensitivity for myocardial ischemia detection in comparison to surface ECG. However, a lack of online systems to quantitatively analyze icECG in real-time prevents its routine use. The present study aimed to develop and validate an autonomous icECG analyzing algorithm.
01A - Beitrag in wissenschaftlicher Zeitschrift
All-inside meniscal repair devices compared with their matched inside-out Vertical mattress suture repair. Introducing 10,000 and 100,000 loading cycles
(SAGE, 01.09.2014) Rosso, Claudio; Müller, Sebastian; Buckland, Daniel M.; Schwenk, Tanja; Zimmermann, Simon; de Wild, Michael; Valderrabano, Victor
All-inside arthroscopic meniscal repairs are favored by most clinicians because of their lower complication rate and decreased morbidity compared with inside-out techniques. Until now, only 1000 cycles have been used for biomechanical testing. Hypothesis: All-inside meniscal repairs will show inferior biomechanical response to cyclic loading (up to 100,000 cycles) and load-to-failure testing compared with inside-out suture controls. Study Design: Controlled laboratory study. Methods: Bucket-handle tears in 72 porcine menisci were repaired using the Omnispan and Fast-Fix 360 (all-inside devices) and Orthocord 2-0 and Ultrabraid 2-0 sutures (matched controls). Initial displacement, displacement after cyclic loading (100, 500, 1000, 2000, 5000, 10,000, and 100,000 cycles) between 5 and 20 N, ultimate load to failure, and mode of failure were recorded, as well as stiffness. Results: Initial displacement and displacement after cyclic loading were not different between the groups. The Omnispan repair demonstrated the highest load-to-failure force (mean 6 SD, 151.3 6 21.5 N) and was significantly stronger than all the other constructs (Orthocord 2-0, 105.5 6 20.4 N; Ultrabraid 2-0, 93.4 6 22.5 N; Fast-Fix 360, 76.6 6 14.2 N) (P \ .0001 for all). The Orthocord vertical inside-out mattress repair was significantly stronger than the Fast-Fix 360 repair (P = .003). The Omnispan (30.8 6 3.5 N/mm) showed significantly higher stiffness compared with the Ultrabraid 2-0 (22.9 6 6.9 N/mm, P \ .0001) and Fast-Fix 360 (23.7 6 3.9 N/mm, P = .001). The predominant mode of failure was suture failure. Conclusion: All-inside meniscal devices show comparable biomechanical properties compared with inside-out suture repair in cyclic loading, even after 100,000 cycles. Clinical Relevance: Eight to 10 weeks of rehabilitation might not pose a problem for all repairs in this worst-case scenario.
01A - Beitrag in wissenschaftlicher Zeitschrift