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Daylight has been associated with multiple health advantages. Some of these claims are associations, hypotheses or beliefs. This review presents an overview of a scientific literature search on the proven effects of daylight exposure on human health. Studies were identified with a search strategy across two main databases. Additionally, a search was performed based on specific health effects. The results are diverse and either physiological or psychological. A rather limited statistically significant and well-documented scientific proof for the association between daylight and its potential health consequences was found. However, the search based on specific health terms made it possible to create a first subdivision of associations with daylight, leading to the first practical implementations for building design.
Studies among people with dementia demonstrated that the sleep quality and rhythm improves significantly when people are exposed to ambient bright light. Since almost half of the healthy older people also indicate to suffer from chronic sleep disorders, the question arises whether ambient bright light can be beneficial to healthy older people. Particularly the effect on sleep/wake rhythm in relation to the exposure to natural light is the focus. It was hypothesised that the sleep quality would be worse in winter due to a lower daylight dose than in summer due to the lower illuminance and exposure duration. A field study was conducted to examine the relationship between daylight exposure and sleep quality in 14 healthy older adults living independently in their own dwellings in the Netherlands. All participants were asked to take part of the study both during the summer period as well as during the winter period. Therefore, they had to wear an actigraph for five consecutive days which measured sleep, activity and light exposure. Results confirmed that people were significantly longer exposed to high illumination levels (>1000 lx) in summer than in winter. Sleep quality measures, however, did not differ significantly between summer and winter. A significant, positive correlation was found between exposure duration to high illuminance from daylight during the day and the sleep efficiency the following night in summer, implying that being exposed to high illuminance for a longer time period has a positive effect on sleep efficiency for the individual data. There was also a tendency of less frequent napping in case of longer exposure duration to light for both seasons. Sleep quality does not differ between summer and winter but is related to the duration of the exposure to bright light the day prior to the night. CC-BY Original article at http://solarlits.com/jd/5-14 http://dx.doi.org/10.15627/jd.2018.2 https://www.dehaagsehogeschool.nl/onderzoek/lectoraten/details/urban-ageing#over-het-lectoraat
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Occupational stress can cause health problems, productivity loss or absenteeism. Resilience interventions that help employees positively adapt to adversity can help prevent the negative consequences of occupational stress. Due to advances in sensor technology and smartphone applications, relatively unobtrusive self-monitoring of resilience-related outcomes is possible. With models that can recognize intra-individual changes in these outcomes and relate them to causal factors within the employee's context, an automated resilience intervention that gives personalized, just-in-time feedback can be developed. This paper presents the conceptual framework and methods behind the WearMe project, which aims to develop such models. A cyclical conceptual framework based on existing theories of stress and resilience is presented as the basis for the WearMe project. The operationalization of the concepts and the daily measurement cycle are described, including the use of wearable sensor technology (e.g., sleep tracking and heart rate variability measurements) and Ecological Momentary Assessment (mobile app). Analyses target the development of within-subject (n=1) and between-subjects models and include repeated measures correlation, multilevel modelling, time series analysis and Bayesian network statistics. Future work will focus on further developing these models and eventually explore the effectiveness of the envisioned personalized resilience system.
Light therapy for older persons with dementia is often administered with light boxes, even though indoor ambient light may more comfortably support the diverse lighting needs of this population. Our objective is to investigate the influence of indoor daylight and lighting on the health of older adults with dementia living in long-term care facilities. A systematic literature search was performed within PubMed, CINAHL, PsycINFO, Web of Science and Scopus databases. The included articles (n=37) were published from 1991 to 2020. These articles researched the influence of existing and changed indoor light conditions on health and resulted in seven categories of health outcomes. Although no conclusive evidence was found to support the ability of indoor light to decrease challenging behaviors or improve circadian rhythms, findings of two studies indicate that exposure to (very) cool light of moderate intensity diminished agitation. Promising effects of indoor light were to reduce depressive symptoms and facilitate spatial orientation. Furthermore, there were indications that indoor light improved one’s quality of life. Despite interventions with dynamic lighting having yielded little evidence of its efficacy, its potential has been insufficiently researched among this study population. This review provides a clear and comprehensive description of the impact of diverse indoor light conditions on the health of older adults with dementia living in long-term care facilities. Variation was seen in terms of research methods, (the description of) light conditions, and participants’ characteristics (types and severity of dementia), thus confounding the reliability of the findings. The authors recommend further research to corroborate the beneficial effects of indoor light on depression and to clarify its role in supporting everyday activities of this population. An implication for practice in long-term care facilities is raising the awareness of the increased lighting needs of aged residents. Original article at: https://doi.org/10.2147/CIA.S297865
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Intelligent environments can offer support to people with early-stage dementia, who often experience problems with maintaining their circadian rhythm. The focus of this work is developing a prototype of an Intelligent Environment for assisting these people with their daily rhythm while living independently at home. Following the four phases of the Empathic Design Framework (Explore, Translate, Process, and Validate), the needs of people with dementia and their caregivers were incorporated into the design. In the exploration phase, a need assessment took place using focus groups (N=12), observations (N=10), and expert interviews (N=27). Then, to determine the requirements for a prototype of an intelligent environment, the second phase, Translate, used three co-creation sessions with different stakeholder groups. In these sessions, Mind Maps (N=55) and Idea Generation Cards (N=35) were used. These resulted in a set of 10 requirements on the following topics: context-awareness, pattern recognition, adaptation, support, personalization, autonomy, modularity, dementia proof interaction, costs, data, and privacy. Finally, in the third phase, the requirements were applied to a real-life prototype by a multidisciplinary design team of researchers, (E-Health) tech companies, designers, software engineers with representatives of eight organizations. The prototype serves as a basis for further development of Intelligent Environments to enable people with dementia to live longer independently at home.
Light profoundly impacts many aspects of human physiology and behaviour, including the synchronization of the circadian clock, the production of melatonin, and cognition. These effects of light, termed the non-visual effects of light, have been primarily investigated in laboratory settings, where light intensity, spectrum and timing can be carefully controlled to draw associations with physiological outcomes of interest. Recently, the increasing availability of wearable light loggers has opened the possibility of studying personal light exposure in free-living conditions where people engage in activities of daily living, yielding findings associating aspects of light exposure and health outcomes, supporting the importance of adequate light exposure at appropriate times for human health. However, comprehensive protocols capturing environmental (e.g., geographical location, season, climate, photoperiod) and individual factors (e.g., culture, personal habits, behaviour, commute type, profession) contributing to the measured light exposure are currently lacking. Here, we present a protocol that combines smartphone-based experience sampling (experience sampling implementing Karolinska Sleepiness Scale, KSS ratings) and high-quality light exposure data collection at three body sites (near-corneal plane between the two eyes mounted on spectacle, neck-worn pendant/badge, and wrist-worn watch-like design) to capture daily factors related to individuals’ light exposure. We will implement the protocol in an international multi-centre study to investigate the environmental and socio-cultural factors influencing light exposure patterns in Germany, Ghana, Netherlands, Spain, Sweden, and Turkey (minimum n = 15, target n = 30 per site, minimum n = 90, target n = 180 across all sites). With the resulting dataset, lifestyle and context-specific factors that contribute to healthy light exposure will be identified. This information is essential in designing effective public health interventions.
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Light intensity and spectral composition notably impact the human circadian rhythm. The human body is a physiological system that regulates its sleep-awake cycle through a constant rhythm of light and darkness. For a long time, the lighting research field has been concerned with understanding this circadian rhythm to improve people's quality of life. To better understand the influence of light on the human circadian rhythm, a remote monitoring device was developed that reliably measures the light spectrum and human circadian rhythm in different environments, including Antarctica and a tropical location study. The designed apparatus aims to facilitate the comprehension of the impact of light on the human circadian rhythm and provide accessible measurements through cost-effective tools. Results show that the developed monitoring prototype can collect and transmit environmental and human data. Therefore, the low-cost equipment developed can be reproduced and used by research institutions to collect data in different environments and improve the understanding of the influence of light on human activities. The cross-sectional analysis of the collected data revealed evidence of the significant influence of light on regulating the human circadian rhythm in tropical and Antarctica case studies. The collected information makes it possible to predict human reactions to the light environment, correlate these responses with seasonal periods, and comprehend how various forms of artificial and natural light interact with individuals and their living spaces. This prototype offers a non-invasive tool for assessing sleep quality and daytime activities, providing knowledge of how lighting conditions can impact overall well-being.
