Spectral imaging has many applications, from methane detection using satellites to disease detection on crops. However, spectral cameras remain a costly solution ranging from 10 thousand to 100 thousand euros for the hardware alone. Here, we present a low-cost multispectral camera (LC-MSC) with 64 LEDs in eight different colors and a monochrome camera with a hardware cost of 340 euros. Our prototype reproduces spectra accurately when compared to a reference spectrometer to within the spectral width of the LEDs used and the ±1σ variation over the surface of ceramic reference tiles. The mean absolute difference in reflectance is an overestimate of 0.03 for the LC-MSC as compared to a spectrometer, due to the spectral shape of the tiles. In environmental light levels of 0.5 W m−2 (bright artificial indoor lighting) our approach shows an increase in noise, but still faithfully reproduces discrete reflectance spectra over 400 nm–1000 nm. Our approach is limited in its application by LED bandwidth and availability of specific LED wavelengths. However, unlike with conventional spectral cameras, the pixel pitch of the camera itself is not limited, providing higher image resolution than typical high-end multi- and hyperspectral cameras. For sample conditions where LED illumination bands provide suitable spectral information, our LC-MSC is an interesting low-cost alternative approach to spectral imaging.
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Recent textile innovations have significantly transformed both the material structures of fibers and fabrics as well as their sphere of use and applications.At the same time, new recycling concepts and methods to re--use textile waste are rapidly being developed and many new ways to make use of recycled and reclaimed fibers have already been found. In this paper, we describe how the development of a new textile, making use of recycled fibers, sparked the development of Textile Reflexes, a robotic textile that can change shape. This paper elaborates on the development of the new textile material, the multidisciplinary approach we take to advance it towards a robotic textile and our first endeavours to implement it in a health & wellbeing context. Textile Reflexes was applied in a vest that supports posture correction and training that was evaluated in a user study. In this way, the paper demonstrates a material and product design study that bridges disciplines and that links to both environmental and social change.doi: 10.21606/dma.2017.610This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License. https://creativecommons.org/licenses/by-nc-sa/4.0/
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Recent advancements in mobile sensing and wearable technologies create new opportunities to improve our understanding of how people experience their environment. This understanding can inform urban design decisions. Currently, an important urban design issue is the adaptation of infrastructure to increasing cycle and e-bike use. Using data collected from 12 cyclists on a cycle highway between two municipalities in The Netherlands, we coupled location and wearable emotion data at a high spatiotemporal resolution to model and examine relationships between cyclists' emotional arousal (operationalized as skin conductance responses) and visual stimuli from the environment (operationalized as extent of visible land cover type). We specifically took a within-participants multilevel modeling approach to determine relationships between different types of viewable land cover area and emotional arousal, while controlling for speed, direction, distance to roads, and directional change. Surprisingly, our model suggests ride segments with views of larger natural, recreational, agricultural, and forested areas were more emotionally arousing for participants. Conversely, segments with views of larger developed areas were less arousing. The presented methodological framework, spatial-emotional analyses, and findings from multilevel modeling provide new opportunities for spatial, data-driven approaches to portable sensing and urban planning research. Furthermore, our findings have implications for design of infrastructure to optimize cycling experiences.
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Katheterablatie is een medische ingreep om een abnormale elektrische verbinding te onderbreken of om een structuur in het hart zodanig te wijzigen dat geen ritmestoornissen meer optreden. Hartritmestoornissen kunnen leiden tot hartfalen of hartstilstand. Katheterablatie is een zeer effectieve methode om hartritmestoornissen te verhelpen die in Nederland gemiddeld 30 keer per dag uitgevoerd. Katheterablatie wordt uitgevoerd met röntgendoorlichting om de positie van de katheter te controleren. De röntgenstraling is schadelijk voor zowel de patiënt als de operateur. Het Haga ziekenhuis in Den Haag heeft een nieuwe unieke faciliteit waar ablaties uitgevoerd kunnen worden in een MRI scanner. Met dit project willen we onderzoeken hoe de positie en vorm van het uiteinde van de katheter ook tijdens een ablatie in de MRI real-time bepaald kan worden, zodat de operateur de operatie efficiënt kan laten verlopen. Optische sensoren lenen zich hier heel goed voor omdat ze niet verstoord worden door het sterke magneetveld van de MRI. Er bestaan systemen die met behulp van glasvezels de vorm en positie van katheters kunnen weergeven, maar deze zijn zeer kostbaar en niet toegespitst op het gebruik bij disposable ablatie-katheters in een MRI. In dit project onderzoeken wij de potentie van een voor deze toepassing specifieke glasvezel-gebaseerde oplossing, waarmee alleen de vorm van het uiteinde van de katheter wordt gemeten en gevisualiseerd, en die bruikbaar is in combinatie met een MRI. Het beoogde resultaat is een prototype van een systeem dat tegen lagere kosten met optische sensoren de vorm en positie van de katheter in een MRI kan weergeven. De projectpartners dragen met hun expertise bij aan de realisatie van dit prototype: fotonica in medische toepassingen (Haagse Hogeschool), sensoren gebaseerd op FBGs (VanderHoekPhotonics), en de medische praktijk en testfaciliteiten (Haga Ziekenhuis ablatiecentrum).
