光环境对节律的生理、心理、情绪等层面影响下的针对睡前状态切换的智能照明设计研究

随着智能建筑与绿色建筑理念的发展，电气照明系统的设计逐渐从单一的照明功能扩展到节能控制与人体舒适度的平衡。传统照明设计在节能与舒适性之间往往难以兼顾，无法满足不同场景下对光照强度、色温、分布均匀性以及动态调节的多样化需求。智能控制系统的引入为照明设计提供了新路径，它通过传感器、控制算法和人机交互界面，实现对照度、色温和光分布的精确调节，并能够依据人的生理节律 and 视觉心理进行适配。文中通过分析建筑电气照明系统的智能控制设计思路，探讨其在提升能源利用效率与人体舒适度方面的作用，研究多维度调控机制与适配策略，提出优化方案与发展方向。研究结果表明，基于智能控制的电气照明系统不仅能够有效降低能耗，还能改善工作与生活环境，促进人机和谐与建筑功能价值的提升。

目前，在邮轮上大部分的情况是人被动的适应环境。如何把智能环境相关技术与邮轮居住空间设计有机结合起来，让“环境去适应人”从而提高用户的舒适度是本文研究的重点。通过文献归纳和总结，得出邮轮居住空间智能化设计原则；通过对空间布局、光、色彩、温湿度等环境要素的智能控制与人体生理指标的动态适应间的关系进行研究，得出人体生理指标与环境参数间适配的规律；针对某邮轮居住舱室要素进行了智能化设计应用研究，使其环境要素能够根据用户的生理和心理的动态变化做出相应的调整，达到提升乘客居住体验的目的。

照明在人类生活、工作和学习中发挥着举足轻重的作用, 除了提供基本的视觉作用(对周围事物的大小、颜色、形状等方面的视觉感知)外, 还会对人的生理、心理功能产生显著影响, 如调节褪黑素分泌、影响生物节律, 促进认知加工、调节由季节变化引起的情绪情感障碍(SAD)等。这种对生理、心理活动产生直接或间接的影响即为照明的非视觉作用。近年来, 照明的非视觉作用及其背后的神经机制得到了研究者的广泛关注和大量实证研究, 并取得了丰硕成果。未来研究需从模型建构、动态照明等角度入手进一步探索照明的非视觉作用及其脑神经机制。

自然灾害不仅给社会带来巨大的经济损失，同时也给灾民带来严重的心理创伤。针对灾后群体产生的负性情绪，以受灾者情绪健康为目标，提出情绪健康的救灾舱方案，旨在探索灾后临时避难设施中缓解受灾者负性情绪的设计策略和方法。通过调研自然灾害的亲历者，并结合灾后产品的特殊性，提出使用虚拟现实(virtual reality, VR)设备研究更广泛的用户群体。根据Kano模型建立功能需求优先级，进行救灾舱设计，并通过生理传感器和VR设备对其内部空间进行循证设计与实验分析。结合实验数据与用户反馈，探讨不同场景对用户负性情绪干预效果的主客观影响。结果表明，本文提出的救灾舱方案具有改善舱内人群负性情绪的效果，其中冷色调−高照度−硬材质、冷色调−高照度−软材质和暖色调−低照度−软材质的组合环境对负性情绪改善效果最佳。本研究为灾后临时安置产品的情绪健康相关设计提供参考。

… The environmental factors investigated were pre-sleep … and moderately satisfying lighting pre-sleep environment can … lx) illuminance are suitable for pre-sleep, and the appropriate CCT …

… subjective alertness compared with the other three lighting. Also, EL1 had significantly … was circadian rhythm phase delay. Two potential thresholds were implied to exist in night lighting …

Background: Insomnia is increasingly recognized for its marked impact on public health and is often associated with various adverse health outcomes, including cardiovascular diseases and mental health disorders. The aim of this study was to investigate the efficacy of pre-sleep dim light therapy (LT) as a non-pharmacological intervention for insomnia in adults, assessing its influence on sleep parameters and circadian rhythms. Methods: A randomized, open-label, two-arm clinical trial was conducted over two weeks with 40 participants aged 20–60 years, all of whom had sleep disorders (CRIS, KCT0008501). They were allocated into control and LT groups. The LT group received exposure to warm-colored light, minimizing the blue spectrum, before bedtime. The study combined subjective evaluation via validated, sleep-related questionnaires, objective sleep assessments via actigraphy, and molecular analyses of circadian clock gene expression in peripheral blood mononuclear cells. Baseline characteristics between the two groups were compared using an independent t-test for continuous variables and the chi-squared test for categorical variables. Within-group differences were assessed using the paired t-test. Changes between groups were analyzed using linear regression, adjusting for each baseline value and body mass index. The patterns of changes in sleep parameters were calculated using a linear mixed model. Results: The LT group exhibited significant improvements in sleep quality (difference in difference [95% CI]; −2.00 [−3.58, −0.43], and sleep efficiency (LT: 84.98 vs. control: 82.11, p = 0.032), and an advanced Dim Light Melatonin Onset compared to the control group (approximately 30 min). Molecular analysis indicated a significant reduction in CRY1 gene expression after LT, suggesting an influence on circadian signals for sleep regulation. Conclusions: This study provides evidence for the efficacy of LT in improving sleep quality and circadian rhythm alignment in adults with insomnia. Despite limitations, such as a small sample size and short study duration, the results underscore the potential of LT as a viable non-pharmacological approach for insomnia. Future research should expand on these results with larger and more diverse cohorts followed over a longer period to validate and further elucidate the value of LT in sleep medicine. Trial registration: The trial was registered with the Clinical Research Information Service (KCT0008501).

ABSTRACT Objectives This study examined the effects of bedroom lighting with pre-bedtime activities two hours before bedtime on sleepiness and polysomnography (PSG) sleep in community-dwelling adults with poor sleep. Methods A balanced crossover design was used with 24 healthy adults. Four lighting conditions under two activity situations (unrestricted (A1) and restricted (A2) electronic device use two hours before bedtime) were tested using adjustable LED lights: (E2: 3000K, 160 lux; E3: 5000K → 3000K, 160 → 30 lux; E4: 5000K, 160 lux) and compared to standard fluorescent lighting (E1: 5000K, 160 lux). The protocol lasted 8 nights (4 lightings × 2 activity conditions), with the whole night PSGmeasure, subjective sleep perception at wake-up, and sleepiness (Stanford Sleepiness Scale) measured hourly 2 hr before bedtime. Results Results showed that sleep latency was 10.62 min longer when exposed to 5000k LED light than to 5000k FL. Exposure to other lower color temperature lights did not have a significant difference in sleepiness and PSGsleep. However, participants felt drowsier and had a shorter PSG sleep latency of 6.08 min when the use of electronic devices was not allowed. Conclusion A 5000k LED light leads to longer sleep latency compared to a 5000k fluorescent light. Restriction of electronic device use before bedtime improves sleep onset in healthy adults. Managing ambient light exposure with lower color temperature LED light and reducing electronic device use 2 hr before bedtime may improve sleep quality in healthy adults.

… time (sleep latency) was 41 ± 42 min; lights out to sleep onset latency was 26 ± 45 min. The … light in entraining the circadian mechanisms of sleep onset. A quiet pre-sleep environment is …

… circadian disruption. Reducing correlated color temperature and light intensity is a common approach to protect circadian … However, the effects of different dynamic transition patterns, …

… of worry and cognitive arousal occurring during the transition to sleep, which can function as … during evening hours minimized circadian disruption [38]. Dimming lights at least one hour …

Abstract Study Objectives Blue-depleted lighting reduces the disruptive effects of evening artificial light on the circadian system in laboratory experiments, but this has not yet been shown in naturalistic settings. The aim of the current study was to test the effects of residing in an evening blue-depleted light environment on melatonin levels, sleep, neurocognitive arousal, sleepiness, and potential side effects. Methods The study was undertaken in a new psychiatric hospital unit where dynamic light sources were installed. All light sources in all rooms were blue-depleted in one half of the unit between 06:30 pm and 07:00 am (melanopic lux range: 7–21, melanopic equivalent daylight illuminance [M-EDI] range: 6–19, photopic lux range: 55–124), whereas the other had standard lighting (melanopic lux range: 30–70, M-EDI range: 27–63, photopic lux range: 64–136), but was otherwise identical. A total of 12 healthy adults resided for 5 days in each light environment (LE) in a randomized cross-over trial. Results Melatonin levels were less suppressed in the blue-depleted LE (15%) compared with the normal LE (45%; p = 0.011). Dim light melatonin onset was phase-advanced more (1:20 h) after residing in the blue-depleted LE than after the normal LE (0:46 h; p = 0.008). Total sleep time was 8.1 min longer (p = 0.032), rapid eye movement sleep 13.9 min longer (p < 0.001), and neurocognitive arousal was lower (p = 0.042) in the blue-depleted LE. There were no significant differences in subjective sleepiness (p = 0.16) or side effects (p = 0.09). Conclusions It is possible to create an evening LE that has an impact on the circadian system and sleep without serious side effects. This demonstrates the feasibility and potential benefits of designing buildings or hospital units according to chronobiological principles and provide a basis for studies in both nonclinical and clinical populations.

This study assesses the effectiveness of pre-sleep dim light therapy (LT) as a non-pharmacological intervention for insomnia in adults, focusing on its impact on sleep quality and circadian rhythms. Conducted over two weeks, the randomized trial involved 40 adults with sleep disorders. Participants were divided into a control group and an LT group, the latter receiving warm-colored light exposure before bedtime. The methodology combined subjective sleep questionnaires, objective sleep assessments through actigraphy, and molecular analyses of circadian clock gene expression in blood cells. Key results indicated significant improvements in the LT group’s sleep quality and efficiency, and a 30-minute advancement in Dim Light Melatonin Onset compared to the control group. Molecular analysis revealed a notable reduction in CRY1 gene expression, implicating LT’s influence on circadian sleep regulation. While the study’s small sample size and short duration limit its scope, the findings suggest LT’s potential as an effective, non-drug approach for insomnia treatment. The study advocates for expanded research with larger, more diverse cohorts over longer periods to further validate LT’s efficacy in sleep medicine.

… sleep closer to their circadian preference, whereas those … Equally relevant, school lighting environments should be … about the extent that described pre-sleep and post-sleep intervals …

Sleep inertia is the brief period of performance impairment and reduced alertness experienced after waking, especially from slow‐wave sleep. We assessed the efficacy of polychromatic short‐wavelength‐enriched light to improve vigilant attention, alertness and mood immediately after waking from slow‐wave sleep at night. Twelve participants (six female, 23.3 ± 4.2 years) maintained an actigraphy‐confirmed sleep schedule of 8.5 hr for 5 nights, and 5 hr for 1 night prior to an overnight laboratory visit. In the laboratory, participants were awakened from slow‐wave sleep, and immediately exposed to either dim, red ambient light (control) or polychromatic short‐wavelength‐enriched light (light) for 1 hr in a randomized crossover design. They completed a 5‐min Psychomotor Vigilance Task, the Karolinska Sleepiness Scale, and Visual Analogue Scales of mood at 2, 17, 32 and 47 min after waking. Following this testing period, lights were turned off and participants returned to sleep. They were awakened from their subsequent slow‐wave sleep period and received the opposite condition. Compared with the control condition, participants exposed to light had fewer Psychomotor Vigilance Task lapses (χ2[1] = 5.285, p = 0.022), reported feeling more alert (Karolinska Sleepiness Scale: F1,77 = 4.955, p = 0.029; Visual Analogue Scalealert: F1,77 = 8.226, p = 0.005), and reported improved mood (Visual Analogue Scalecheerful: F1,77 = 8.615, p = 0.004). There was no significant difference in sleep‐onset latency between conditions following the testing period (t10 = 1.024, p = 0.330). Our results suggest that exposure to polychromatic short‐wavelength‐enriched light immediately after waking from slow‐wave sleep at night may help improve vigilant attention, subjective alertness, and mood. Future studies should explore the potential mechanisms of this countermeasure and its efficacy in real‐world environments.

Light can influence many psychophysiological functions beyond vision, including alertness, circadian rhythm, and sleep, namely the non‐image forming (NIF) effects of light. Melanopic equivalent daylight illuminance (mel‐EDI) is currently recommended as the predictor of the NIF effects of light. Although light dose is also critical for entraining and regulating circadian cycle, it is still unknown whether relatively low mel‐EDI light exposure for prolonged duration in the evening would affect pre‐sleep arousal and subsequent sleep. In all, 18 healthy college students (10 females, mean [standard deviation] age 21.67 [2.03] years) underwent 2 experimental nights with a 1 week interval in a simulated bedroom environment. During experimental nights, participants were either exposed to high or low mel‐EDI light (73 versus 38 lx mel‐EDI, 90 versus 87 photopic lx at eye level, 150 photopic lx at table level) for 3.5 h before regular bedtime, and their sleep was monitored by polysomnography. Subjective sleepiness, mood, and resting‐state electroencephalography during light exposure were also investigated. Results showed no significant differences in sleep structure and sleep quality between the two light conditions, whereas 3.5 h of exposure to high versus low mel‐EDI light induced marginally higher physiological arousal in terms of a lower delta but higher beta power density before sleep, as well as a lower delta power density during sleep. Moreover, participants felt happier before sleep under exposure to high versus low mel‐EDI light. These findings together with the current literature suggest that evening prolonged relatively low mel‐EDI light exposure may mildly increase arousal before and during sleep but affected sleep structure less.

At its best, human-centric lighting considers the visual and non-visual effects of light in support of positive human outcomes. At its worst, it is a marketing phrase used to healthwash lighting products or lighting design solutions. There is no doubt that environmental lighting contributes to human health, but how might one practice human-centric lighting given both the credible potential and the implausible hype? Marketing literature is filled with promises. Technical lighting societies have summarized the science but have not yet offered design guidance. Meanwhile, designers are in the middle, attempting to distinguish credible knowledge from that which is dubious to make design decisions that affect people directly. This article is intended to: (1) empower the reader with fundamental understandings of ways in which light affects health; (2) provide a process for human-centric lighting design that can dovetail with the decision-making process that is already a part of a designer's workflow.

… Lighting uses light, and light is unique among the … talk about human-centric lighting mean is lighting that considers … visual performance and comfort to sleep quality, alertness, mood and …

This paper discusses the rise of human-centric lighting and its current status in lighting. We summarise the human benefits associated with light and lighting and show that human-centric lighting has sound motivations, despite being tainted by misleading marketing claims. The phrase integrative lighting avoids the hype and encapsulates what lighting aspires to be. Embodied in these concepts are some things old and some things new. The old is twofold. First, without diminishing the value of lighting products, the core ingredient for good human outcomes is good design, driven by a design team. Second, light is still for vision, and lighting for visibility, visual comfort and visual amenity is as important as ever. Complementing the old is new awareness and responsibility for how light and lighting influence non-visual responses in humans. Circadian, neuroendocrine and neurobehavioural responses are important for human health and should be considered on-par with visual responses. This awareness leads toward lighting design solutions with increased contrast between day and night. The parties responsible for addressing non-visual responses to light and lighting are evolving. Architects, lighting professionals, lighting equipment manufacturers, medical professionals, building owners and individuals all have a stake, but who should drive decisions and in what proportion?

In recent years, the main area of interest in the issue of influencing mental states of people is the impact of lighting on human beings, their wellbeing but also workplace productivity. This work discusses in detail the problem of positively influencing people using intelligent technologies, especially the role of the colors. We describe techniques and technologies needed to implement the case study of an intelligent lighting system. The system proposed can detect humans from an IP camera, find faces, and detect emotion. The main aim is to adjust the lights accordingly to the emotional result to improve the mood of people while taking into consideration the principles of color psychology and daytime. We have evaluated our case study solution in a real-world environment and collected the feedback from participants in the form of a questionnaire. Evaluation of participants’ wellbeing was based on their subjective statements. There were several ideas on further functionality extension which needs to be explored. Among them is including wearable devices to the proposed system, validate the emotional results according to them, but also determine the impact of an increasing number of users interacting with the system at the same time.

Human centric lighting is an umbrella concept which covers human health and well-being in general. As the conventional lighting techniques are based on horizontal workplane illuminance, it drives from the vertical eye level illuminance and its spectral distribution triggering the non-visual effects on humans. That is named as melanopic illuminance consequently. Its metrics have taken their place in lighting design literature and applications, with emergence of related standards subsequently. This literature overview contributes about the understanding the meaning human centric lighting due to transition from visual to non-visual effects of light, and how they direct recent research through light's impacts on human performance, emotions health and well-being, and relations to energy saving even. The shift from the concept of human centric lighting to circadian lighting design is obvious in very current studies.

… SSL, makes the concept of Human-centric Lighting created. Human-centric lighting (HCL) is all types … aspects, compared to types of light that follow a traditional lighting perspective[22]. …

Increased blue-enriched morning light is often said to support circadian rhythm synchronization. Through a better sleep quality, one's cognitive and emotional functioning can also be enhanced. However, it is unclear which light characteristics (especially illuminance at eye level) are necessary to obtain a wellbeing effect in employees. This field study investigated different lighting conditions in a truck factory. 71 shift workers participated in the study during their morning shift (6 am - 2 pm). Measurements of sleep (MotionWatch8), attention (D2 attention task, go no-go computer task) and visual comfort (questionnaire) were administered before and after changing the lighting conditions. A Human Centric Lighting-condition (HCL; vertical melanopic equivalent daylight illuminance (MEDI) = 250 lux, CCT=5000 K; N = 33) was compared with a control LED-condition (MEDI = 44 lux, CCT=4000K; N = 38). Results show that workers in the HCL-condition showed a larger improvement in sleep efficiency (p=.057) and concentration (p=.01) than the control LED-group. No differences were found in visual comfort between groups. Preliminary results are promising and show that 250 MEDI might be a sufficient cut-off to stimulate workers' sleep and cognition. The high illuminance level was not detrimental in the HCL condition for the perceived visual comfort. Blue-enriched morning light supports sleep and concentration in shift workers. High illuminance levels are not detrimental for the perceived visual comfort.

… In this chapter, we will explore how human- centric lighting (HCL) can help improve our health and … move into sleep more smoothly and makes their sleep better. Humancentric lighting is …

In the past, people have spent most of their time in an outdoors and in the sunlight. Nowadays, people spend most of their time in an indoors such as home, office, hospital, school and under the lights of artificial lighting sources. Daylight is dynamic due to changes in parameters such as color temperature, light intensity, light color during the day according to the change in the position of the sun. In contrast, lighting provided by artificial light sources is constant throughout the day. The human circadian rhythm and its associated biological clock are synchronized with the light dark cycle of the world. Therefore, depending on the lighting that is exposed in indoor environments, problems may arise due to the deterioration of the circadian rhythm of people. The idea of human centric lighting emerged in order to create a dynamic atmosphere of sunlight in people’s life and working areas and to prevent the deterioration of the biological clock and circadian rhythms. In this study, human centric lighting and its effects are discussed.

… for recognizing how light influences sleep, mood and overall health. From the 1960s through the 1980s, research into the psychological impact of lighting showed that bright, cool light …

… and sleep duration, sleep timing, and sleep quality across … light exposure and its influence on sleep behaviors. So, it … in sleep duration was associated with lower sleep quality, we …

The global phenomenon of population aging presents a significant challenge, affecting both the increasing number of older individuals and their duration of living with disability. Tailored care services are crucial for improving the quality of life of older adults, particularly those with disabilities residing in nursing homes. However, ensuring personalized care and mitigating the risks associated with institutionalization are essential in optimizing care quality. One particular challenge in nursing homes is maintaining residents' personal routines and addressing sleep disturbances linked to neurodegenerative disorders. Non-pharmacological interventions are increasingly recognized as preventive and management strategies for behavioral and psychiatric symptoms in nursing home residents. Sleep disruptions, such as reduced duration and increased nocturnal awakenings, are prevalent among nursing home residents. Excessive nocturnal lighting and frequent caregiver interventions contribute to these disturbances. This study aimed to investigate the impact of implementing smart humancentric lighting on the sleep efficiency of nursing home residents. Data from pressure sensors embedded in mattresses were collected to assess sleep efficiency. The findings suggest that smart humancentric lighting can significantly reduce sleep disturbances and improve sleep quality in nursing home residents. Future research should delve into specific symptoms, care burden, and psychotropic agent utilization to validate the effectiveness of this intervention.

… human-centric lighting luminaires and compared with the corresponding human centric lighting metrics in order to create a lighting … and human-centered lighting. The different SPDs …

This study presents a literature review on human centric lighting, utilizing solid-state lighting and switchable glazing, which has immense potential to create comfortable and productive environments. Windows and shading devices of a building are the essential components that allow natural daylight to enter indoors, thereby maintaining a relationship between the interior and exterior environments. Artificial light sources are always integrated with natural light to provide the right lighting environment. Achieving a balance between natural and artificial light is crucial; the efficiency depends on how effectively artificial light is combined with daylight. This paper explores the benefits of intelligent solid-state lighting and switchable glazing technology in creating a comfortable and energy-efficient environment. Lighting metrics for assessing circadian entrainment and algorithms for optimizing visual and thermal comfort along with energy efficiency are the main topics of concern. By optimizing lighting and temperature control, workplaces can increase productivity and promote circadian entrainment. This review considers papers mainly from 2004 to 2023, challenges and problems in implementation, along with future directions are also considered. If the right spectrally controllable source is designed by giving a suitable light exposure for the right duration, it is possible to achieve comfort, health, and energy efficiency. This integrative lighting solution provides new and innovative ways to enhance our daily lives. Climate-responsive algorithms seem more reliable for switchable glazing; overall circadian performance improves when mixed with natural light.

Abstract Background Evidence‐based interventions to improve the sleep–wake rhythm, mood and behaviour in older adults with intellectual disabilities (ID) are limited. Increasing light exposure has been shown to be effective in improving the sleep–wake rhythm, mood, and behaviour in other populations. The current study investigates the effect of installing environmental dynamic lighting in common living rooms of care facilities on sleep–wake rhythm, mood, and behaviour in older adults with ID. Methods A non‐randomised, non‐concurrent, multiple baseline study was performed from October 2017 to May 2018. Fifty‐four participants [mean (SD) age of 63.42 (8.6) years, 65% female] in six care facilities were included. All participants had three baseline measurements (Weeks 1, 5 and 9). Dynamic lighting was installed in Week 10, after which three intervention measurements took place (Weeks 12, 17 and 24). Sleep characteristics and the sleep–wake rhythm were assessed using actigraphy (GENEActiv). Mood was measured with the Anxiety, Depression and Mood Scale (ADAMS) and behaviour with the Aberrant Behaviour Checklist (ABC). Results Mixed‐effect regression analysis showed a worsening of the primary outcome interdaily stability (P = 0.001). This could be attributed to one care facility, whereas interdaily stability did not change in the other care facilities (P = 0.74). Dynamic lighting led to earlier mid‐sleep (P = 0.003) and sleep onset (P < .0001) and improved mood as indicated by lower scores on the ADAMS depression (−0.64 SD, P < 0.001) and social avoidance (−0.47 SD, P = 0.004) subscales. The prevalence of screening above cut‐off for depression decreased from 23 to 9.8% (OR = .16, P = 0.003). For behaviour, a decrease was seen in hyperactivity (−0.43 SD, P < 0.001), lethargy (−0.35 SD, P = 0.008) and irritability (−0.33 SD, P < .001) as measured with the ABC. No adverse effects were reported. Conclusion Installing dynamic lighting in common living areas for older adults with ID improved the mood and behaviour of the residents up to 14 weeks after placement. Integrated dynamic lighting is a promising, undemanding and potentially effective addition to improve mood and behaviour in care organisations for people with ID, but does not seem to do so by improving sleep or sleep–wake rhythms.

In this paper, our design aims to assist in sleep inertia reduction and avoid the startle response and irritation caused by alarm-made unpleasant wakeup stimuli. Thus, we propose an approach that employs a soft and alerting sunrise simulation, conditionally utilizes natural light, and appropriately lowers the bedroom temperature for awakening a sleeper tenderly and gradually to gain full alertness. This approach is inspired by known scientific implications confirming the effectiveness of lights and temperatures on wakefulness. In this regard, we present an economical do-it-yourself digital tech-assisted system for bedroom lighting and temperature control. The system design is based on the smartphone and Internet of Things (IoT) technology. We develop the hardware and software in the system for implementing three IoT-based control tasks. One is the tuning of artificial light brightness using the pulse width modulation technique. Another is the opening of the window curtain using stepper motor control and light detection. The other is the activation of the air-conditioning setting using an infrared remote control and temperature detection. We construct a testbed for conducting experiments. Experimental results demonstrate that the proposed system can execute task requirements satisfactorily. The proposed system is promising for achieving our goal. It embodies features of sustainability.

Circadian adaptation to shifted sleep/wake schedules may be facilitated by optimizing the timing, intensity and spectral characteristics of light exposure, which is the principal time cue for mammalian circadian pacemaker, and possibly by strategically timing nonphotic time cues such as exercise. Therefore, circadian phase resetting by light and exercise was assessed in 44 healthy participants (22 females, mean age [±SD] 36.2 ± 9.2 years), who completed 8‐day inpatient experiments simulating night shiftwork, which included either an 8 h advance or 8 h delay in sleep/wake schedules. In the advance protocol (n = 18), schedules were shifted either gradually (1.6 h/day across 5 days) or abruptly (slam shift, 8 h in 1 day and maintained across 5 days). Both advance protocols included a dynamic lighting schedule (DLS) with 6.5 h exposure of blue‐enriched white light (704 melanopic equivalent daylight illuminance [melEDI] lux) during the day and dimmer blue‐depleted light (26 melEDI lux) for 2 h immediately before sleep on the shifted schedule. In the delay protocol (n = 26), schedules were only abruptly delayed but included four different lighting conditions: (1) 8 h continuous room‐light control; (2) 8 h continuous blue‐enriched light; (3) intermittent (7 × 15 min pulses/8 h) blue‐enriched light; (4) 8 h continuous blue‐enriched light plus moderate intensity exercise. In the room‐light control, participants received dimmer white light for 30 min before bedtime, whereas in the other three delay protocols participants received dimmer blue‐depleted light for 30 min before bedtime. Both the slam and gradual advance protocols induced similar shifts in circadian phase (3.28 h ± 0.37 vs. 2.88 h ± 0.31, respectively, p = .43) estimated by the change in the timing of timing of dim light melatonin onset. In the delay protocol, the continuous 8 h blue‐enriched exposure induced significantly larger shifts than the room light control (−6.59 h ± 0.43 vs. −4.74 h ± 0.62, respectively, p = .02). The intermittent exposure induced ~60% of the shift (−3.90 h ± 0.62) compared with 8 h blue‐enriched continuous light with only 25% of the exposure duration. The addition of exercise to the 8 h continuous blue‐enriched light did not result in significantly larger phase shifts (−6.59 h ± 0.43 vs. −6.41 h ± 0.69, p = .80). Collectively, our results demonstrate that, when attempting to adapt to an 8 h overnight work shift, delay shifts are more successful, particularly when accompanied by a DLS with high‐melanopic irradiance light stimulus during wake.

In modern society, the average person spends more than 90% of their time indoors. However, despite the growing scientific understanding of the impact of light on biological mechanisms, the existing light in the built environment is designed predominantly to meet visual performance requirements only. Lighting can also be exploited as a means to improve occupant health and well-being through the circadian functions that regulate sleep, mood, and alertness. The benefits of well-lit spaces map across other regularly occupied building types, such as residences and schools, as well as patient rooms in healthcare and assisted-living facilities. Presently, Human Centric Lighting is being offered based on generic insights on population average experiences. In this paper, we suggest a personalized bio-adaptive office lighting system, controlled to emit a lighting recipe tailored to the individual employee. We introduce a new mathematical optimization for lighting schedules that align the 24-h circadian cycle. Our algorithm estimates and optimizes parameters in experimentally validated models of the human circadian pacemaker. Moreover, it constrains deviations from the light levels desired and needed to perform daily activities. We further translate these into general principles for circadian lighting. We use experimentally validated models of the human circadian pacemaker to introduce a new algorithm to mathematically optimize lighting schedules to achieve circadian alignment to the 24-h cycle, with constrained deviations from the light levels desired for daily activities. Our suggested optimization algorithm was able to translate our findings into general principles for circadian lighting. In particular, our simulation results reveal: (1) how energy constrains drive the shape of optimal lighting profiles by dimming the light levels in the time window that light is less biologically effective; (2) how inter-individual variations in the characteristic internal duration of the day shift the timing of optimal lighting exposure; (3) how user habits and, in particular, late-evening light exposure result in differentiation in late afternoon office lighting.

Abstract Study Objective Night work has detrimental impacts on sleep and performance, primarily due to misalignment between sleep–wake schedules and underlying circadian rhythms. This study tested whether circadian-informed lighting accelerated circadian phase delay, and thus adjustment to night work, compared to blue-depleted standard lighting under simulated submariner work conditions. Methods Nineteen healthy sleepers (12 males; mean ± SD aged 29 ± 10 years) participated in two separate 8-day visits approximately 1 month apart to receive, in random order, circadian-informed lighting (blue-enriched and dim, blue-depleted lighting at specific times) and standard lighting (dim, blue-depleted lighting). After an adaptation night (day 1), salivary dim-light melatonin onset (DLMO) assessment was undertaken from 18:00 to 02:00 on days 2–3. During days 3–7, participants completed simulated night work from 00:00 to 08:00 and a sleep period from 10:00 to 19:00. Post-condition DLMO assessment occurred from 21:00 to 13:00 on days 7–8. Ingestible capsules continuously sampled temperature to estimate daily core body temperature minimum (Tmin) time. Tmin and DLMO circadian delays were compared between conditions using mixed effects models. Results There were significant condition-by-day interactions in Tmin and DLMO delays (both p < .001). After four simulated night shifts, circadian-informed lighting produced a mean [95% CI] 5.6 [3.0 to 8.2] hours greater delay in Tmin timing and a 4.2 [3.0 to 5.5] hours greater delay in DLMO timing compared to standard lighting. Conclusions Circadian-informed lighting accelerates adjustment to shiftwork in a simulated submariner work environment. Circadian lighting interventions warrant consideration in any dimly lit and blue-depleted work environments where circadian adjustment is relevant to help enhance human performance, safety, and health.

Evening exposure to short-wavelength light has disruptive effects on circadian rhythms and sleep. These effects can be mitigated by blocking short-wavelength (blue) frequencies, which has led to the development of evening blue-depleted light environments (BDLEs). We have previously reported that residing 5 days in an evening BDLE, compared with residing in a normal indoor light environment of similar photopic lux, advances circadian rhythms and increases the duration of rapid eye movement (REM) sleep in a randomized cross-over trial with twelve healthy participants. The current study extends these findings by testing whether residing in the evening BDLE affects the consolidation and microstructure of REM sleep in the same sample. Evening BDLE significantly reduces the fragmentation of REM sleep (p = 0.0003), and REM sleep microarousals in (p = 0.0493) without significantly changing REM density or the latency to first REM sleep episode. Moreover, the increased accumulation of REM sleep is not at the expense of NREM stage 3 sleep. BDLE further has a unique effect on REM sleep fragmentation (p = 0.0479) over and above that of circadian rhythms phase-shift, indicating a non-circadian effect of BDLE. If these effects can be replicated in clinical populations, this may have a therapeutic potential in disorders characterized by fragmented REM sleep.

ABSTRACT This study aimed to clarify the situation of light exposure and examine the relationship between light exposure and bedtime/wake-up time during school days (SD), holidays (HD), and a long-stay camp period (CP) in Japanese children. After data cleaning, the final subjects were 29 children (10.2 ± 1.2 years old, 25 boys and 4 girls) who participated in paid long-term camp programs in the summers of 2019 and 2021. Data on light exposure, bedtime, and wake-up time were collected. The results of the comparison of the total high-intensity light exposure (HLE) hours for each survey period confirmed that HLE was high before the 18:00 zone in CP, and that for SD and HD were high after the 19:00 zone. Furthermore, the longer the total HLE hours before the 18:00 zone and the shorter those after the 19:00 zone were significantly earlier with both bedtime and wake-up time. These findings indicate that daytime and nighttime light exposure in children’s actual living environment is related to their bedtime and wake-up time, and that camping and going to school may be important factors to ensure children’s adequate daytime light exposure.

Background Light is the primary synchronizing cue for the circadian timing system, capable of exerting robust physiological effects, even with very dim and/or brief photic exposure. Mammals, including humans, are particularly susceptible to light at night. As such, measures of light in the sleeping environment are critical for evaluating sleep health. Sleep diaries provide inexpensive measures of sleep, but do not typically include light information. Methods Four questions probing visual perception of light in the bedtime and waking environments were added to the Consensus Sleep Diary for Morning administration. As part of a lighting intervention study, 18 hospital Labor and Delivery Department personnel completed the sleep diary for 1 week in each of two experimental conditions while wearing Actiwatch devices equipped with photosensors. Diary responses were evaluated against photosensor values from the beginning and end of each rest interval (n=194 rest intervals), as well as against sleep measures, utilizing linear mixed models. Results Responses to light questions were related to actual light measures at bedtime, controlling for shift type and experimental condition. In addition, subjective light information at bedtime and waking was related to both objective and subjective sleep parameters, with data generally indicating poorer sleep with light in the sleeping environment. Conclusion Questions addressing perception of light in the sleeping environment may provide a crude yet affordable metric of relative photic intensity. Further, as responses relate to sleep outcomes, subjective light information may yield valuable insights regarding mechanisms and outcomes of clinical significance in sleep and circadian research.

… The results of this study suggest that pre-sleep light exposure to different color … the light intensity of the different color temperatures remains unchanged. Exposure of 6700K light with a …

… sleep periods, but not during pre-sleep periods. Polysomnography and skin temperature … In summary, the effects of pre-sleep exposure to a cold ambient temperature and bright lighting …

… humidity (40%, 55%, 70%), and pre-sleep as well as pre-awakening illuminance (30 lux, 90 … not weaken the significance of light environment in the comprehensive sleep environment. …

To determine the sound and light combined conditions pollution in urban residential environments at night, this paper comprehensively evaluates cross-visual and auditory sensory channels in the laboratory. Experimental variables include extremum and gradient, and the working state of the participants was determined and verified. A subjective evaluation experiment on 18 combined conditions was carried out by synthesizing real-world data. Results from the sound and light combined conditions experiment show that there are significant differences in the tolerance limits of participants to different content sound variables (p = 0.000 < 0.05, p = 0.033 < 0.05, p = 0.002 < 0.05). Among them, the traffic noise (p = 0.000 < 0.05) has the greatest impact on the tolerance limits of people, followed by birdsong (p = 0.033 < 0.05) and human voice (p = 0.002 < 0.05). There is no difference in the tolerance limits of light pollution (p = 0.288 > 0.05, p = 0.122 > 0.05, p = 0.146 > 0.05) at different color temperatures. The tolerance limits of participants will not be reduced due to the superposition of two interference variables: sound pollution and light pollution. Adding light pollution to sound pollution can increase the tolerance limits of participants, while adding sound pollution to light pollution has no significant effect on the tolerance limits. The study also found that adding light with different color temperatures to the human voice can increase participants’ tolerance limit to human voice (1% -2%), indicating that visual elements can change individuals’ perception of sound. In addition, the physiological and psychological differences between participants may affect the performance differences of individual participants in sound and light combined conditions.

… Background: The level of indoor lighting … evening lighting period is a critical window for light exposure among the Chinese elderly. Methods: This study conducted a pre-sleep lighting …

… significantly increased by exposing either to bright lights of 10 000 lx or to … light (100 lx). However, LF was significantly increased at REM sleep, when compared with that at the pre-sleep …

Sleep is an essential physiological process, and residential lighting environments significantly impact sleep quality. To address circadian phase delays exacerbated by pre-sleep smartphone use in youth, this study developed targeted lighting interventions. Through laboratory simulations, the effects of color temperature, illuminance, and horizontal blue light ratio on multisensory responses (visual, psychological, physiological) and sleep quality were examined. A rhythmic lighting strategy for healthy environments was proposed. Key findings: (1) Lighting factors revealed a hierarchy of influence on sleep quality—color temperature had the greatest influence on sleep quality, followed by illuminance and horizontal blue light ratio. Optimal conditions include cycling color temperature, 800 lx illuminance, and 25% blue light ratio. (2) Context-specific interventions were proposed—high illuminance with low color temperature enhances comfort in healthcare/leisure spaces, while medium–high color temperature, high illuminance, and cycling blue light ratios improve efficiency in office/study environments. (3) A time-sequenced rhythmic lighting scheme aligned with daily routines was implemented. This study establishes a novel health evaluation framework for residential lighting, combining sleep quality, psychological, and physiological metrics, redefines research paradigms for light-induced health effects, and provides actionable insights for optimizing workplace lighting.