Authentische Verdeckung virtueller 3D-Objekte in Bilderwelten

Das Ziel dieser Arbeit ist es, eine authentische Verdeckung eingebetteter virtueller 3D-Objekte in augmentierten Bilderwelten bei einer geringen Anzahl an Fotos innerhalb der Bilderwelt zu erreichen. Für die Verdeckung von realen und virtuellen Anteilen einer Augmented Reality-Szene sind Tiefeninformationen notwendig. Diese stammen üblicherweise aus einer 3D-Rekonstruktion, für deren Erstellung sehr viele Eingangsbilder notwendig sind. Im Gegensatz dazu wurde in dieser Arbeit ein System entwickelt, das eine vollständige 3D-Rekonstruktion umgeht. Dieses beruht auf einem direkten bildbasierten Rendering-Ansatz, welcher auch mit unvollständigen Tiefeninformationen eine hohe Bildqualität in Bezug auf eine authentische Verdeckung erreicht. Daraus erschließen sich neue Anwendungsgebiete, wie z.B. die automatisierte Visualisierung von 3D-Planungsdaten und 3D-Produktpräsentationen in Bildern bzw. Bilderwelten, da in diesen Bereichen oftmals nicht genügend große Bildmengen vorhanden sind. Gerade für diese Anwendungsgebiete sind authentische Verdeckungen für die Nutzerakzeptanz der Augmentierung wichtig. Unter authentischer Verdeckung wird die entsprechend der menschlichen Wahrnehmung visuell korrekte Überlagerung zwischen virtuellen Objekten und einzelnen Bildanteilen eines oder mehrerer Fotos verstanden. Das Ergebnis wird in Form einer Bilderwelt (eine bildbasierte 3D-Welt, die die Fotos entsprechend der Bildinhalte räumlich anordnet) präsentiert, die mit virtuellen Objekten erweitert wurde. Folglich ordnet sich diese Arbeit in das Fachgebiet der Augmented Reality ein. Im Rahmen dieser Arbeit wurde ein Verfahren für die bildbasierte Darstellung mit authentischen Verdeckungen auf der Basis von unvollständigen Tiefeninformationen sowie unterschiedliche Verfahren für die notwendige Berechnung der Tiefeninformationen entwickelt und gegenübergestellt. Das Sliced-Image-Rendering-Verfahren rendert mithilfe unvollständiger Tiefeninformationen ein Bild ohne 3D-Geometrie als dreidimensionale Darstellung und realisiert auf diese Weise eine authentische Verdeckung. Das Berechnen der dafür notwendigen Tiefeninformationen eines 2D-Bildes stellt eine gesonderte Herausforderung dar, da die Bilderwelt nur wenige und unvollständige 3D-Informationen der abgebildeten Szene bereitstellt. Folglich kann eine qualitativ hochwertige 3D-Rekonstruktion nicht durchgeführt werden. Die Fragestellung ist daher, wie einzelne Tiefeninformationen berechnet und diese anschließend größeren Bildbereichen zugeordnet werden können. Für diese Tiefenzuordnung wurden im Rahmen der vorliegenden Arbeit drei verschiedene Verfahren konzipiert, die sich in Bezug auf genutzte Daten und deren Verarbeitung unterscheiden. Das Segment-Depth-Matching-Verfahren ordnet Segmenten eines Bildes mithilfe der 3D-Szeneninformationen der Bilderwelt eine Tiefe zu. Hierfür werden Segmentbilder vorausgesetzt. Als Ergebnis liegt für jedes Foto eine Depth-Map vor. Um eine Tiefenzuordnung auch ohne eine vorangehende Segmentierung zu ermöglichen, wurde das Key-Point-Depth-Matching-Verfahren entwickelt. Bei diesem Verfahren werden die 3D-Szeneninformationen der Bilderwelt auf die Bildebene als kreisförmige Sprites projiziert. Die Distanz zur Kamera wird dabei als Tiefenwert für das Sprite verwendet. Alle projizierten Sprites einer Kamera ergeben die Depth-Map. Beide Verfahren liefern Flächen mit Tiefeninformationen, aber keine pixelgenauen Depth-Maps. Um pixelgenaue Depth-Maps zu erzeugen, wurde das Geometry-Depth-Matching-Verfahren entwickelt. Bei diesem Verfahren wird eine Szenengeometrie des abgebildeten Szenenausschnittes erzeugt und dadurch eine pixelgenaue Depth-Map erstellt. Hierfür wird ein semiautomatischer Skizzierungsschritt vorausgesetzt. Die erzeugte Szenengeometrie stellt keine vollständige 3D-Rekonstruktion der Bilderweltenszene dar, da nur ein Szenenausschnitt aus Sicht einer Kamera rekonstruiert wird. Anhand einer technischen Umsetzung erfolgte eine Validierung der konzeptionellen Verfahren. Die daraus resultierenden Ergebnisse wurden anhand verschiedener Bilderweltenszenen mit unterschiedlichen Eigenschaften (Außen- und Innenraumszenen, detailreich und -arm, unterschiedliche Bildmengen) evaluiert. Die Evaluierung des Sliced-Image-Renderings zeigt, dass mithilfe unvollständiger Tiefeninformationen der entwickelten Depth-Matching-Verfahren und unter Einhaltung der gestellten Anforderungen (wenig Eingabefotos, kleine Szenen, keine 3D-Rekonstruktion) eine authentische Verdeckung eingebetteter virtueller 3D-Objekte in Bilderwelten realisiert werden kann. Mithilfe des entwickelten Systems können bildbasierte Anwendungen auch mit kleinen Fotomengen Augmentierungen mit hoher Bildqualität in Bezug auf eine authentische Verdeckung realisieren.The goal of this work is the authentic occlusion of embedded virtual objects in augmented photo collections by using only a small number of photos. The realization of occlusions of virtual and real objects in an Augmented Reality application require depth information. Usually this information is computed by performing a complete 3D reconstruction of the image-based scene, which requires a big number of input photos. In contrast, in this work a system was developed, which based on a direct image-based rendering approach without performing a 3D reconstruction. This image-based rendering approach works with incomplete depth information and realizes a high image quality regarding authentic occlusion. This work opens up new scopes of application like automatic visualization of 3D planning data and 3D product presentations in photos or photo collections, because in these scopes a large number of input photos is often not available. Especially for these application areas authentic occlusions are important for the user acceptance of an augmentation. An authentic occlusion is the visually, correct superimposition of virtual objects and image parts of one or more photos according to human perception. The result is presented as an augmented photo collection. A photo collection is an image-based 3D world, in which the photos are spatialized by their visual content. Thus, this work is part of the field of research Augmented Reality. In context of this work, an approach for image-based rendering with authentic occlusions based on incomplete depth information and several approaches for computing the necessary depth information were developed. The Sliced-Image-Rendering technique uses the incomplete depth information to render 2D images as a three-dimensional relief in order to realize an authentic occlusion of embedded virtual objects. The computation of necessary depth information of a 2D image represents a separate challenge, because a high-quality 3D reconstruction cannot be performed. Thus, the question is how individual depth information can be computed and mapped to larger image areas. In this work, three depth mapping approaches were developed that differ in terms of used data and their processing. The Segment-Depth-Matching technique assigns depth to image segments using the 3D scene information of the photo collection. This assumes segment images. As a result, for each photo a depth map exists. To allow a depth mapping even without a prior segmentation, the Key-Point-Depth-Matching technique has been developed. In this technique, the 3D scene information of the photo collection is projected onto the image plane as circular sprites. All projected sprites of an image are combined to produce the corresponding depth map. Both techniques produce surfaces with depth information, but no pixel-accurate depth maps. To create pixel-accurate depth maps, the Geometry-Depth-Matching technique has been developed. In this method, geometry is generated for the region that is visible in a photo and thereby a pixel-accurate depth-map is created. The generation of geometry requires a semi-automatic segmentation step. The generated scene geometry is not a full 3D reconstruction of the global scene shown in complete photo collection, as only geometry for a single image is generated. The approaches were implemented into a system and validated. The subsequent results are analyzed and evaluated in terms of authentic occlusion by using several scenes with different properties (exterior and interior scenes, rich and poor in detail, different number of input photos) as test data. The evaluation of the Sliced-Image-Rendering technique shows that authentic occlusion can be realized by using incomplete depth information obtained by the developed depth-matching techniques. With the aid of the developed system in this work, image-based applications can realize augmentations with high image quality in terms of an authentic occlusion even though only a small number of input photos is given

Counting young carers in Switzerland – a study of prevalence

An online survey of children in school grades 4–9 (mostly aged 10–15) was conducted in order to determine the prevalence of young carers in Switzerland using a 2‐stage stratified sampling approach. 4082 respondents were drawn from 230 schools. A total of 3991 respondents were included in the analysis and of these 307 (7.7%) were identified as young carers. The population estimate of prevalence was 7.9 per cent. This suggests that there are around 38 400 young carers in school grades 4–9 in Switzerland. Extrapolating to the 9–16 age group gives a figure of almost 51 500

Pain Interventions for people with dementia: a quasi-experimental study

Abstract Background Due to the complexity of the provision of care for people with dementia, pain assessment and management is still considered to be lacking. An optimal way to support frontline staff in providing pain assessment and management for people with dementia living in nursing homes has not yet been identified. The success of supporting interventions seems dependent on contextual factors in the nursing homes. This study, therefore, analyzes the feasibility of a nurse-led training intervention, using repeated on-site case studies, in modifying pain intensity and frequency in people with dementia. Methods Using a quasi-experimental design, we undertook a multi-center study of nurse-led training in pain management, with subsequent on-site case studies. Healthcare workers from 3 nursing homes assessed pain in 164 residents with dementia over 147 days. We used mixed-effect growth curve models with spline regression to analyze the data. Results We found that on-site case studies support frontline staff with pain management and assessment. Repeated reflection in case studies led to significantly longer pain free intervals (from 4.7 at baseline to 37.1 days at second follow-up) and decreased frequency of pain events (OR 0.54 at first follow-up and 0.43 at second follow-up). However no trends regarding pain intensity could be found. Therefore, on-site case studies may be valuable for improving pain frequency and pain-free intervals over time. Conclusion This feasibility study shows the potential of on-site support for frontline nursing home staff. On-site case studies may also affect health outcomes in people with dementia. However, the complexity of dementia care necessitates the management of a broader range of needs. Trial registration The study was retrospectively registered on the tenth of January 2017 with the German registry of clinical trials (DRKS00009726)

Evaluation of intracranial stenting in a simulated training and assessment environment for neuroendovascular procedures

PurposeGiven the inherent complexity of neurointerventional procedures and the associated risks of ionizing radiation exposure, it is crucial to prioritize ongoing training and improve safety protocols. The aim of this study is to assess a training and evaluation in-vitro environment using a vascular model of M1 stenosis, within a clinical angiography suite, without relying on animal models or X-ray radiation.Materials and methodsUsing a transparent model replicating M1 stenosis, we conducted intracranial stenting procedures with four different setups (Gateway & Wingspan, Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse). A video camera was integrated with the angiography system’s monitor for real-time visualization, while a foot switch was employed to simulate live fluoroscopy. Three neuroradiologists with varying levels of expertise performed each procedure for three times. The total duration of fluoroscopy as well as the time from passing the stenosis with the wire to completion of the procedure were recorded using a dedicated software designed for this experimental setup.ResultsCompared to the Gateway & Wingspan procedure, the total fluoroscopy time reduced significantly with the Gateway & Enterprise, Neurospeed & Acclino, and Pharos Vitesse procedures by 51.56 s, 111.33 s, and 144.89 s, respectively (p < 0.001). Additionally, physicians with under 2 years and over 5 years of experience reduced FT by 62.83 s and 106.42 s, respectively, (p < 0.001), compared to a novice physician. Similar trends were noted for the time of wire distal to stenosis, with significant reductions for Neurospeed & Acclino and Pharos Vitesse compared to both Gateway & Wingspan as well as Gateway & Enterprise (all p < 0.001).ConclusionProcedures requiring wire exchange maneuvers exhibited nearly twice the fluoroscopy time in comparison to balloon-mounted stenting or stent-placement via PTA balloon catheters. The more experienced neuroradiologist demonstrated significantly quicker performance in line with expectations in a real-life clinical setting, when compared to the less experienced interventionalist. This in-vitro setup allowed the evaluation of alternative technical approaches and differences in experience of operators without the use of animal models or X-ray. The setup combines advantages of simulators and silicone vessel models in a realistic working environment

Parent-of-origin-specific allelic associations among 106 genomic loci for age at menarche.

Age at menarche is a marker of timing of puberty in females. It varies widely between individuals, is a heritable trait and is associated with risks for obesity, type 2 diabetes, cardiovascular disease, breast cancer and all-cause mortality. Studies of rare human disorders of puberty and animal models point to a complex hypothalamic-pituitary-hormonal regulation, but the mechanisms that determine pubertal timing and underlie its links to disease risk remain unclear. Here, using genome-wide and custom-genotyping arrays in up to 182,416 women of European descent from 57 studies, we found robust evidence (P < 5 × 10(-8)) for 123 signals at 106 genomic loci associated with age at menarche. Many loci were associated with other pubertal traits in both sexes, and there was substantial overlap with genes implicated in body mass index and various diseases, including rare disorders of puberty. Menarche signals were enriched in imprinted regions, with three loci (DLK1-WDR25, MKRN3-MAGEL2 and KCNK9) demonstrating parent-of-origin-specific associations concordant with known parental expression patterns. Pathway analyses implicated nuclear hormone receptors, particularly retinoic acid and γ-aminobutyric acid-B2 receptor signalling, among novel mechanisms that regulate pubertal timing in humans. Our findings suggest a genetic architecture involving at least hundreds of common variants in the coordinated timing of the pubertal transition

Caring in mind? Professionals’ awareness of young carers and young adult carers in Switzerland

Findings from international research emphasis the need of these young people to be identified and recognised. Therefore, a nationwide quantitative study of professionals' awareness was conducted in the Swiss context. Data were collected from professionals working in education, healthcare and social services. The study examined professionals’ familiarity with the terms used to describe young people with caring responsibilities; their ability to identify the population in their professional context; their perception of the relevance of the issue; their ability to support them; and their own training needs. Potential study participants were contacted via email. Data were collected using an online survey, which was open for 14 weeks during the period of September to December 2016. Survey data from 2,311 professionals, who reported being regularly in contact with young people with caring responsibilities in their occupational context, were included for analysis. Of all terms presented in the survey, young carer (YC) was the term most familiar to all professionals. Among healthcare and education sector, the percentage of professionals familiar with this term was higher than that among professionals from social services. Professionals from social services were the most likely to consider the issue relevant to their work, those from education were the least likely. Professionals who were familiar with the terms describing YC were more likely to consider the issue relevant to their work. Study results showed that more than half of the respondents had not identified young people with caring responsibilities, and that the ability of participants to identify YC was related to their occupational sector. The perceived ability to support YC was related to their reported ability to recognise them. In order to enable professionals to support YC, raising awareness, providing training for professionals and a national network of existing organisations should be well considered