光环境对节律的生理、心理、情绪等层面影响下的帮助睡前状态切换的智能照明产品设计研究

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。

光照除了传统的视觉作用外, 还具有一定的非视觉效应, 包括调节昼夜节律、褪黑素分泌和警觉性等生理功能和行为表现。随着光照对生理节律影响研究的不断深入, 近来很多学者开始关注光照的警觉性作用。我们根据最新研究进展总结了：(1)警觉性的测量工具; (2)光照强度、时长、时间点、波长、色温等对光照警觉性作用的影响; (3)光照在治疗情绪障碍、调节生理节律、完善办公照明方面的应用; (4)提出了继续探讨光照警觉性作用的神经机制、优化参数特征和探讨混淆变量的研究方向。

光的非视觉生物效应与人体健康密切相关，随着LED在室内照明中的广泛应用，LED照明与人体生理健康的关系也日益重要。心电图(ECG，electrocardiograph)是生理参数的主要表征之一。针对LED照明，以3种色温(3 000、5 000、6 500 K)、5种照度(300、500、750、1 000、1 500 lx)为主要变量，研究不同光照时长(10、20 min)下，老年人心电指标对光响应的情况。结果显示，照度、色温等光照参数的主效应对老年人的ECG无显著影响，但照度和色温的交互作用对老年人的ECG影响显著。其中，3 000 K和1 000 1x的交互作用对P波时间和T波时间影响最大；6 500 K和1 500 1x的交互作用影响最小；5 000 K和750 1x的交互作用对PR间期影响最大，6 500 K和500 1x的交互作用影响最小。但较短光照时长下，老年人的ECG变化不明显。因此，有必要探讨更长时间(1 h及以上)光照下，老年人的心电生理响应情况，从而为老年人健康照明参数的确定提供依据。

Abstract Study Objectives Shiftwork is associated with cognitive impairment and reduced sleep time and quality, largely due to circadian misalignment. This study tested if circadian-informed lighting could improve cognitive performance and sleep during simulated night shifts versus dim control lighting. Methods Nineteen healthy participants (mean ± SD 29 ± 10 years, 12 males, 7 females) were recruited to a laboratory study consisting of two counterbalanced 8-day lighting conditions (order randomized) 1-month apart: (1) control lighting condition - dim, blue-depleted and (2) circadian-informed lighting condition - blue-enriched and blue-depleted where appropriate. Participants underwent an adaptation night (22:00–07:00 hours), then four nights of simulated night work (cognitive testing battery of nine tasks, 00:00–08:00 hours), and sleep during the day (10:00–19:00 hours). Psychomotor vigilance task (PVT) lapses, Karolinska Sleepiness Scale (KSS) scores, and polysomnography-derived sleep outcomes were compared between conditions and across days using mixed models. Results Significant condition-by-day-by-time of task interaction effects were found for PVT lapses, median reaction time, and reaction speed, with ~50% fewer lapses by the end of simulated shift work with circadian-informed lighting versus control (mean ± SD 7.4 ± 5.0 vs. 15.6 ± 6.1). KSS was lower around the night shift midpoints on days 6 and 7 with circadian versus control lighting. Participants slept 52 minutes longer [95% CIs: 27.5, 76.5 minutes] by day 7 with circadian-informed versus control lighting, p < .001. Effects were inconsistent on other performance tasks. Conclusions Circadian-informed lighting improved sleep, sleepiness, and vigilance compared to control lighting. These findings support the potential for lighting interventions to improve sleep and vigilance in night shift workers chronically exposed to dim lighting.

Circadian hygiene, a concept not to be confused with the notion of public or social hygiene, should be discussed among experts and society. Light–dark cycles and other possible synchronizers of the human circadian timing system affect ways of life, including sleeping, eating, working and physical activity. Some of these behaviors have also been investigated individually as synchronizers (e.g., eating times). Therefore, the knowledge held today about circadian rhythms, and their implications for health, allows future perspectives in this field to be mapped. The present article summarizes the latest knowledge on factors influencing circadian rhythms to discuss a perspective for the future of health promotion based on circadian hygiene. However, it is important to highlight that circadian hygiene is the product of an imbrication of individual and societal involvement. First, it is important to adopt practices and devise public health policies in line with circadian hygiene. Second, individual healthy habits require internal rhythms to be examined. Last, the research agenda on circadian hygiene can be developed on a public as well as individual level, raising the question as to how much society is willing to embrace this change.

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 Objectives The study aimed to, for the first time, (1) compare sleep, circadian phase, and alertness of intensive care unit (ICU) nurses working rotating shifts with those predicted by a model of arousal dynamics; and (2) investigate how different environmental constraints affect predictions and agreement with data. Methods The model was used to simulate individual sleep-wake cycles, urinary 6-sulphatoxymelatonin (aMT6s) profiles, subjective sleepiness on the Karolinska Sleepiness Scale (KSS), and performance on a Psychomotor Vigilance Task (PVT) of 21 ICU nurses working day, evening, and night shifts. Combinations of individual shift schedules, forced wake time before/after work and lighting, were used as inputs to the model. Predictions were compared to empirical data. Simulations with self-reported sleep as an input were performed for comparison. Results All input constraints produced similar prediction for KSS, with 56%–60% of KSS scores predicted within ±1 on a day and 48%–52% on a night shift. Accurate prediction of an individual’s circadian phase required individualized light input. Combinations including light information predicted aMT6s acrophase within ±1 h of the study data for 65% and 35%–47% of nurses on diurnal and nocturnal schedules. Minute-by-minute sleep-wake state overlap between the model and the data was between 81 ± 6% and 87 ± 5% depending on choice of input constraint. Conclusions The use of individualized environmental constraints in the model of arousal dynamics allowed for accurate prediction of alertness, circadian phase, and sleep for more than half of the nurses. Individual differences in physiological parameters will need to be accounted for in the future to further improve predictions.

Ocular light exposure has important influences on human health and well-being through modulation of circadian rhythms and sleep, as well as neuroendocrine and cognitive functions. Prevailing patterns of light exposure do not optimally engage these actions for many individuals, but advances in our understanding of the underpinning mechanisms and emerging lighting technologies now present opportunities to adjust lighting to promote optimal physical and mental health and performance. A newly developed, international standard provides a SI-compliant way of quantifying the influence of light on the intrinsically photosensitive, melanopsin-expressing, retinal neurons that mediate these effects. The present report provides recommendations for lighting, based on an expert scientific consensus and expressed in an easily measured quantity (melanopic equivalent daylight illuminance (melaponic EDI)) defined within this standard. The recommendations are supported by detailed analysis of the sensitivity of human circadian, neuroendocrine, and alerting responses to ocular light and provide a straightforward framework to inform lighting design and practice.

… circadian patterns that mark the transitions between daytime and nighttime, but they have different forms and are differentially affected by light exposure, sleep and circadian … readiness. …

Carefully timed light exposure is a promising countermeasure to overcome the negative sleep and circadian implications of shift work. However, many lighting interventions are static and applied at the group level (e.g. light banks, changes to ambient lighting), which is not appropriate for all populations or settings. This study investigates whether individualized lighting exposure, via personal light treatment devices (PLTDs), can improve sleep, sustain projected performance, and entrain circadian rhythms with the work schedules of US Navy submariners. Submarines are a unique testbed for PLTD intervention because they provide a self-contained environment with little influence from outside schedules or lighting. Forty-two submariners were pseudo-randomly assigned to either the PLTD or Control group. PLTD group participants wore blue-light exposure glasses for ~40 minutes upon waking and blue-blocking glasses for ~2 hours before sleep; Control group participants did not use PLTDs. Both groups completed questionnaires assessing subjective sleep and mood before and after the 12-day intervention, and wore wrist actigraphy devices to objectively assess sleep, projected performance, and predicted circadian phase outcomes. Compared with the Control group, several objective and subjective sleep outcomes and projected performance scores were improved in the PLTD group. The PLTD group's predicted circadian phase (modeled from actigraphy-derived accelerometer data) more rapidly shifted to align with scheduled work periods. Compliance with PLTD use was high, with no major disruptions to operational duties reported. These data provide initial support for the use of PLTDs as a flexible and customizable countermeasure for fatigue, sleep loss, and circadian misalignment in an operational environment.

and alertness), the relationship is typically nonlinear such that even short duration and moderate intensity exposures can induce larger than expected responses compared to longer duration high-intensity exposures. Guyett, Scott, and colleagues tested the use of moderate-intensity, short-wavelength enriched, longer-duration light exposure to improve circadian adaptation, sleep, and neurobehavioral performance in the context of submariner work. Optimization of lighting depends on individual differences, organizational requirements, and work environments. To enable widespread adoption and implementation, we require larger studies testing the effectiveness and documenting return on investment. Further work must consider tailoring light interventions to address individual variability and ensure scalability through integration with other health and wellness initiatives.

The circadian rhythm, called Process C, regulates a wide range of biological processes in humans including sleep, metabolism, body temperature, and hormone secretion. Light is the dominant synchronizer of the circadian rhythm—it has been used to regulate the circadian phase to cope with jet-lag, shift work, and sleep disorder. The homeostatic oscillation of the sleep drive is called Process S. Process C and Process S together determine the sleep-wake cycle in what is known as the two-process model. This paper addresses the regulation of both Process C and Process S by scheduling light exposure and sleep based on numerical simulations of circadian rhythm and sleep mathematical models. This is a significant step beyond the existing literature that only considers the entrainment of Process C. Regulation of the two-process model poses several unique features and challenges: 1. Process S is non-smooth, i.e., the homeostatic dynamics are different in the sleep and wake regimes; 2. Light only indirectly affects Process S through Process C; 3. Light does not affect Process C during sleep. We consider two scenarios: optimizing light intensity as the control input with spontaneous (i.e., unscheduled) sleep/wake times and jointly optimizing the light intensity and the sleep/wake times, which allows limited delayed sleep and early waking as part of the decision variables. We solve the time-optimal entrainment problem for the two-process model for both scenarios using an extension of the gradient descent algorithm to non-smooth systems. To illustrate the efficacy of our time-optimal entrainment strategies, we consider two common use cases: transmeridian travelers and shift workers. For transmeridian travelers, joint optimization of the two-process model avoids the unrealistic long wake duration when only Process C is considered. The entrainment time also decreases when both the light input and the sleep schedule are optimized compared to when only the light input is optimized. For shift workers, we show that the entrainment time is significantly shortened by optimizing the night shift working light.

… lamps, the incandescent source found a ready application in the production of unique and … an impact on the human circadian system and cause possible sleep disorders, effects that …

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.

… measurement device were important for drawing valid inferences in sleep and circadian … While there is continuing debate in the field as to whether we are ready for applications, a …

Light is the primary circadian time cue, but there are large interindividual differences in how sensitive the circadian system is to light. Currently, it is not well understood how individual differences in light sensitivity interact with real-world light environments to determine sleep and circadian timing. We used a validated computational model to simulate sleep and circadian timing (predicted dim light melatonin onset) under realistic assumptions about light and work schedules. Simulations were repeated varying light sensitivity (translated to equivalent ED50 values for interpretability), as well as evening, morning, and daytime illuminances. Brighter evening light led to later predicted circadian and sleep timing, with this effect being amplified by high light sensitivity. Reducing evening light was particularly beneficial for those with high light sensitivity or a long circadian period. Brighter morning light was beneficial for individuals with a long circadian period, or those with both high light sensitivity and high evening light. However, bright morning light could be maladaptive in individuals with a short circadian period or those with low light sensitivity and low evening light. Brighter daytime light attenuated the delaying effects of evening artificial light across conditions, indicating that increasing daytime light was the most universally beneficial lighting intervention. Our results demonstrate how circadian light sensitivity can be used to tailor individual-level solutions that support optimal sleep and circadian timing.

Misalignment between the environment and one’s circadian system is a common phenomenon (e.g., jet lag) which can have myriad negative effects on physical and mental health, mental and physiological performance, and sleep. Absent any intervention, the circadian system adjusts only 0.5-1.0 h per day to a shifted light-dark and sleep-wake schedule. Bright light facilitates circadian adjustment, but in field studies, bright light is only modestly better than no stimulus. Evidence indicates that exercise and melatonin can be combined with bright light to elicit larger shifts but no study has combined all of these stimuli or administered them at the times that are known to elicit the largest effects on the circadian system. The aims of this study are to compare the effects of different treatments on circadian adjustment to simulated jet lag in a laboratory. Following 2 weeks of home recording, 36 adults will spend 6.5 consecutive days in the laboratory. Following an 8 h period of baseline sleep recording on the participant’s usual sleep schedule on Night 1 (e.g., 0000-0800 h), participants will undergo a 26 h circadian assessment protocol involving 2 h wake intervals in dim light and 1 h of sleep in darkness, repeated throughout the 26 h. During this protocol, all urine voidings will be collected; mood, sleepiness, psychomotor vigilance, and pain sensitivity will be assessed every 3 h, forehead temperature will be assessed every 90 min, and anaerobic performance (Wingate test) will be tested every 6 h. Following, the circadian assessment protocol, the participant’s sleep-wake and light dark schedule will be delayed by 8 h compared with baseline (e.g., 0800-1400 h), analogous to travelling 8 times zones westward. This shifted schedule will be maintained for 3 days. During the 3 days on the delayed schedule, participants will be randomized to one of 3 treatments: (1) Dim Red Light + Placebo Capsules, (2) Bright Light Alone, (3) Bright Light + Exercise + Melatonin. During the final 26 h, all conditions and measures of the baseline circadian protocol will be repeated. Acclimatization will be defined by shifts in circadian rhythms of aMT6s, psychomotor vigilance, Wingate Anaerobic performance, mood, and sleepiness, and less impairments in these measures during the shifted schedule compared with baseline. We posit that Bright Light Alone and Bright Light + Exercise + Melatonin will elicit greater shifts in circadian rhythms and less impairments in sleep, mood, performance, and sleepiness compared with Dim Red Light + Placebo Capsules. We also posit that Bright Light + Exercise + Melatonin will elicit greater shifts and less impairments than Bright Light Alone.

… simulation framework for personalized lighting conditions, revealing how tailored lighting strategies can influence melatonin suppression, daytime alertness, and pre-sleep drowsiness. …

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.

… the context of emerging human-centric technologies like Human-Centric Lighting (HCL) and … Cool light (5500K) was less relaxing and had minimal impact on sleep quality. Pre-sleep …

As vehicles become extensions of the living environment, automotive interior lighting for non-driving activities like napping is gaining significant interest. This study investigates the effects of illuminance and correlated color temperature (CCT) on subjective perception and mood states in in-vehicle napping and waking scenarios. A within-subjects experiment was conducted in a vehicle mockup where participants were exposed to lighting conditions before napping and after waking. The lighting conditions comprised three eye-level illuminance values (10 $\mathrm{~lx}, 150 \mathrm{~lx}, 300 \mathrm{~lx}$) and two CCTs (warm white light, $\sim 2000 \mathrm{~K}$; natural white light, $\sim 4500 \mathrm{~K}$). Subjective evaluations of happiness, comfort, tension, glare, brightness, satisfaction, as well as positive/negative affect (using the Positive and Negative Affect Schedule, PANAS) were collected. Results revealed that for the napping scenario, lower illuminance significantly increased comfort and reduced tension. For the waking scenario, a low CCT significantly enhanced comfort. The tested lighting parameters did not, however, produce a significant impact on positive or negative affect in either scenario. There was a significant difference in perception of the same light stimulus between pre-nap and post-nap states, particularly for happiness, comfort, tension ratings and positive affect. Furthermore, the study demonstrated a brightness perception saturation effect around1|50 lx within the confined vehicle space, indicating a higher sensitivity to light compared to larger, open-plan indoor environments. In conclusion, this research provides evidencebased recommendations: lower illuminance is preferable for inducing sleep, while low-CCT light is better for a comfortable awakening.

… , with each subject experiencing three pre-sleep lighting environments on different dates with … The proposed framework provides practical solutions for human-centric lighting design in …

Implementing novel, human-centric building control strategies that account for the interaction of multidomain factors, light, temperature, and time of day, can enhance occupant comfort and promote energy savings. However, their successful implementations require a robust framework that clearly explains the physiological mechanisms through which light exposure influences thermal perception and evaluation. To date, most studies have primarily relied on the hue-heat hypothesis, which attributes changes in thermal assessment solely to visual color associations, overlooking the physiological impact of light, particularly blue-enriched bright light, on the circadian rhythm and thermoregulation. In this study, we investigated the influence of light intensity on thermal physiology, perception, and behavior within a circadian context, employing skin temperature measurements, subjective questionnaires, and fan-use behavior as outcome measures. 20 healthy adults participated in four experimental sessions combining two illuminance levels (bright vs. dim, with identical spectral composition) at two times of day (07:00 and 14:00) under warm conditions, both steady-state and fan-induced dynamic ones. Results showed that skin temperature followed its natural circadian rhythm, being lower in the early morning than at midday. Notably, bright light exposure significantly suppressed the circadian rise in skin temperature in the morning, shifted thermal sensation votes from slightly warm towards neutral, and improved thermal comfort votes compared to dim light or midday exposure. This effect was evident under steady-state warm conditions and persisted following fan use. In contrast, under the fan-induced slightly cool condition, neither light intensity nor time of day significantly affected thermal assessment. These findings underscore the fundamental role of circadian physiology in thermal comfort and suggest that strategically timed light and thermal exposure can optimize comfort by aligning ambient conditions with the body’s internal rhythms.

Light exposure triggers a range of physiological and behavioural responses that can improve and challenge health and well-being. Insights from laboratory studies have recently culminated in standards and guidelines for measuring and assessing healthy light exposure, and recommendations for healthy light levels. Implicit to laboratory paradigms is a simplistic input-output relationship between light and its effects on physiology. This simplified approach ignores that humans actively shape their light exposure through behaviour. This article presents a novel framework that conceptualises light exposure as an individual behaviour to meet specific, person-based needs. Key to healthy light exposure is shaping behaviour, beyond shaping technology. Biller et al explain that humans actively shape their lighting environment through behaviour to meet specific individual needs. They propose that achieving healthy light exposure relies on shaping behaviour.

… effects also depend on factors not captured by the LEBA, such as prior light exposure, ambient indoor lighting, and light exposure across a longer pre-sleep window 61,76 . Consistent …

As an integral part of human chronobiology, the circadian system plays a crucial role in regulating key biological functions, including sleep and the intricate hormonal rhythms of melatonin (MLT) and cortisol (CORT). Scholars have increasingly recognized environmental stressors as significant contributors to disturbed sleep patterns. Albeit vigorously discussed individually, the literature lacks comprehensive insights into the synergistic effect of artificial light at night (ALAN) and noise. The aim of this review is to look into the intricate interplay of the ALAN effects on sleep architecture, the modulation of circadian function, and how this influences homeostatic sleep. Furthermore, ALAN suppresses MLT secretion, which is most pronounced in response to short wavelengths of light. In addition, this review will demonstrate how exposure to noise during sleep elevates CORT and noradrenaline levels, which contributes to stress-related diseases and sleep disturbances. ALAN and noise, persistently emitted into the environment, share intrinsic mechanisms with comparable characteristics. Therefore, understanding their combined impact has become increasingly urgent. Pre-sleep exposure to both ALAN and noise acts as a potent stressor, with the potential to disrupt sleep patterns. Interestingly, during sleep, noise emerges as the predominant influence on sleep quality. Moreover, these stressors often synergize and amplify one another’s adverse effects. Thus, limiting their exposure is crucial for cultivating a sustainable environment conducive to quality sleep and overall well-being.

… light, currently used in most general lighting fixtures, suggests that narrow bandwidth blue LED light may be stronger than 4,000 K white fluorescent light for suppressing melatonin. …

… the non-visual channel, affecting emotions, sleep … lighting and daylighting, both of which are separated from each other in terms of standards and research. However, integrated lighting …

… health, well-being, activity and sleep. Comfortable … the non-visual impact of light on humans and the recommendations of experts regarding the standardization of integrated lighting …

Light simultaneously induces visual and non-visual effects. Although the differences in the spectral sensitivity of intrinsic photosensitive retinal ganglion cells induce opposing influences on physiological responses, it is difficult to independently measure only non-visual effects. Therefore, the reported effects of light color on physiological responses are inconsistent. This study aimed to clarify the visual and non-visual effects of light color on physiological responses. Three different conditions were employed to construct a lighting environment in which light colors were difficult to perceive due to chromatic adaptation and change blindness: constant white light (baseline condition), a gradual transition from white to blue light, and a gradual transition from white to red light. The physiological responses (brain activity, heart rate variability, and electrodermal activity) of 21 participants were measured with and without light color perception. The results suggested that blue light causes more non-visual effects compared to red light as blue light induces brain activation in some regions of the PFC (p < 0.05) and increases sweating, although the differences were not statistically significant. A mean comparison suggested that the visual effects of blue light showed tendencies toward a calming role for the prefrontal cortex and inhibition of sweating, but the differences were not statistically significant. Another mean comparison suggested that the visual effects of red light tended to enhance sweating, but the differences were not statistically significant. Visual and non-visual effects did not cause significant differences in heart rate variability. Additionally, a mean comparison did not reveal any significant tendencies.

International standard CIE S 026:2018 provides lighting professionals and field researchers in chronobiology with a method to characterize light exposures with respect to non-visual photoreception and responses. This standard defines five spectral sensitivity functions that describe optical radiation for its ability to stimulate each of the five α-opic retinal photoreceptor classes that contribute to the non-visual effects of light in humans via intrinsically-photosensitive retinal ganglion cells (ipRGCs). The CIE also recently published an open-access α-opic toolbox that calculates all the quantities and ratios of the α-opic metrology in the photometric, radiometric and photon systems, based on either a measured (user-defined) spectrum or selected illuminants (A, D65, E, FL11, LED-B3) built into the toolbox. For a wide variety of ecologically-valid conditions, the melanopsin-based photoreception of ipRGCs has been shown to account for the spectral sensitivity of non-visual responses, from shifting the timing of nocturnal sleep and melatonin secretion to regulating steady-state pupil diameter. Recent findings continue to confirm that the photopigment melanopsin also plays a role in visual responses, and that melanopsin-based photoreception may have a significant influence on brightness perception and aspects of spatial vision. Although knowledge concerning the extent to which rods and cones interact with ipRGCs in driving non-visual effects is still growing, a CIE position statement recently used melanopic equivalent daylight (D65) illuminance in preliminary guidance on applying “proper light at the proper time” to manipulate non-visual responses. Further guidance on this approach is awaited from the participants of the 2nd International Workshop on Circadian and Neurophysiological Photometry (in Manchester, August 2019). The new α-opic metrology of CIE S 026 enables traceable measurements and a formal, quantitative specification of personal light exposures, photic interventions and lighting designs. Here, we apply this metrology to everyday light sources including a natural daylight time series, a range of LED lighting products and, using the toobox, to a smartphone display screen. This collection of examples suggests ways in which variations in the melanopic content of light over the day can be adopted in strategies that use light to support human health and well-being.

… is still in its infancy, it is already suggesting that lighting could be a means of addressing issues of attentiveness, drowsiness, and sleep regulation. Studies have shown the body to be …

… or action spectrum for all non-visual effects of light. The … of the spectrum of lamps for non-visual biological use. The spectrally … They do not yet feel sleepy and do not yet like to go to bed. …

… However, the magnitude and nature of these non-visual effects depend on a complex and … while daytime exposure strengthens circadian alignment and improves sleep quality6,12,14; a …

… drive and the alerting force determines when we fall asleep and how well we sleep at night. … , WJM: Non-visual biological effect of lighting and the practical meaning for lighting for work. …

Abstract Since the discovery of non-visual effect of light, consequences on human psychology and physiology have been investigated; however, effects on cognition of exposure to different spectral composition have been partially explored. Aim of this paper is an overview on researches developed in this field to compare general approaches and measurements protocols: the scarce knowledge of the physiological mechanisms, as well as the lack of shared methods, techniques, tools and procedures represent the weak point of this research. The impact of different procedures and experimental settings on results is shown, evidencing the need for scientifically consistent and internationally agreed procedures.

The analysis of scientific papers revealed that the majority of studies in the field of lighting control systems are devoted to energy conservation, and single-user interaction with lighting. At the same time, the issue related to the impact of lighting on human stress levels in an educational environment is covered only by a number of studies that have investigated lighting parameters for different types of human activities. While there are known dependencies of the positive influence of lighting on reducing conflict behavior and stress levels in multi-user spaces, there is no mechanism for adapting appropriate lighting systems to the psycho-emotional state of users of such spaces. The paper presents the analysis of scientific publications and patents on non-visual effects of lighting on human body. The effects of lighting on conflict behavior and stressful state of a person were studied when using adaptive lighting systems. The methods and approaches of the developed adaptive lighting systems and the constraints associated with these methods were analyzed. The results of theoretical and experimental studies are given. A set of methods and tools to create an intelligent multi-user adaptive lighting system is proposed.

… adaptive lighting system for seniors. However, several aspects differ from our work: (1) only white lighting was used and no accent lights, (2) lighting … comprised not only lighting, but also …

As the influence of indoor environments on human emotional regulation and cognitive function becomes increasingly critical in modern society, there is a growing need for intelligent lighting systems that dynamically respond to users’ emotional states. While previous studies have investigated either illuminance or color in isolation, this study concentrates on quantitatively analyzing the interaction of these two key elements on human emotion and cognitive control capabilities. Utilizing electroencephalography (EEG) and electrocardiography (ECG) signals, we measured participants’ physiological responses and subjective emotional assessments in 18 unique lighting conditions, combining six colors and three levels of illuminance. The results confirmed that the interaction between light color and illuminance significantly affects physiological indicators related to emotion regulation. Notably, low-illuminance purple lighting was found to promote positive emotions and inhibit negative ones by increasing frontal alpha asymmetry (FAA) and gamma wave activity. Conversely, low-illuminance environments generally diminished cognitive reappraisal and negative emotion inhibition capabilities. Furthermore, a random forest model integrating time-series data from EEG and ECG predicted emotional valence and arousal with accuracies of 87% and 79%, respectively, demonstrating the validity of multi-modal physiological signal-based emotion prediction. This study provides empirical data and a theoretical foundation for the development of human-centered, emotion-adaptive lighting systems by presenting a quantitative causal model linking lighting, physiological responses, and emotion. These findings also provide a biomimetic perspective by linking lighting-induced physiological responses with emotion regulation, offering a foundation for the development of adaptive lighting systems that emulate natural light–human interactions.

… Plus, the wrong color temperature can affect your mood and emotions, affecting your bottom … The main task of the driver in this work is to regulate the brightness of the light using a PWM …

Light is a common ambient medium to express additional information in a peripheral and calm way, but it is also an environmental stimulant to create atmosphere, evoke moods, and provide immersive experiences. Through the design of the DeLight system, we aim to establish a biofeedback-driven lighting environment that informs users about their stress level for intervention and assists them in biofeedback relaxation training. In this study, DeLight is interfaced with a heart rate variability biofeedback system with two modes for different purposes: stress intervention and relaxation assistance. We evaluated the prototype of DeLight in two user studies. The results of the first study show that DeLight has the potential for stress intervention; the HRV biofeedback through the changes of ambient light could improve a user’s awareness of stress and trigger behavioral conditioning, such as deep breathing. The results of the second study confirm that DeLight has potential as a new biofeedback interface for relaxation assistance; biofeedback through an immersive lighting environment can support physiological regulation as effectively as graphic biofeedback; it offers enhanced relaxation effects regarding both subjective experience and physiological arousal. These findings suggest that the biofeedback-driven ambient light can perform as persuasive technology in the domain of health self-management. The combination of decorative and informative aspects enables the lighting interface to offer the users a comfortable and relaxing condition for biofeedback-assisted relaxation training.

… based intelligent lighting systems and researching adaptive lighting systems for emotional regulation. It provides quantitative lighting parameter references for implementing emotional …

In the field of modern biomedical science, biomechanics focuses on the mechanical properties and interactions of molecules, cells, tissues, and organs, which is crucial for a deeper understanding of how the human body perceives and adapts to changes in the external environment. As an important environmental factor, light’s impact on the human body not only involves psychological and physiological aspects, but is also closely related to biomechanical mechanisms. Therefore, this study aims to explore the regulatory effects of light on residents’ emotions and physiological rhythms from a biomechanical perspective, providing a new perspective for revealing the mysteries of the interaction between light and the human body. By measuring physiological parameters such as heart rate, respiration, and skin conductance response, investigate whether there is a certain resonance between exposure to light of different wavelengths (red, green, blue) or color temperatures (3000 K, 6000 K) and hearing. The results indicate that auditory or visual environmental stimuli can indeed cause changes in human physiological parameters and emotions; The dynamic lighting environment has a stronger impact on emotional perception; Revealed the feasibility of using physiological parameters as the basis for acousto-optic fusion perception and judgment. Understanding the relationship between color and psychology is crucial for creating a living environment that meets people’s psychological needs. Finally, summarize the principles of human living environment lighting design based on color psychology, providing guidance for future design practices. This study reveals the intrinsic relationship between light and human biomechanical response by measuring a series of biomechanical related indicators, providing scientific basis for optimizing human living environment design.

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.

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。

智慧生活正在逐步走向以数据驱动和人本服务为核心的发展阶段，居住空间的功能边界不断被重塑。智能家居不再局限于设备的远程控制，而是在更深层次上实现网络传输和环境调节的多维融合。基于此，本文探讨了“融合高速网络”“运用智能算法”“强化数据分析”“注重人机融合”“完善安全体系”以上五项策略，旨在推动室内空间向高效运行和个性化服务双重目标靠近，强调家居体验的连贯性、安全性在整体设计中的整合价值。

OBJECTIVES Recent evidence indicates that adolescents' motivation to change sleep-wake patterns is low, despite significant impact of adolescent sleep problems on many areas of daytime functioning. The aim of the present study is to evaluate components of adolescents' motivation, and subsequent changes in behaviour. METHODS Fifty-six adolescents, aged 13-23 (M = 15.8 ± 2.3 y; 38% m) diagnosed with Delayed Sleep-Wake Phase Disorder (DSWPD) underwent three therapy sessions involving bright light therapy to phase advance sleep patterns. Adolescents were instructed to advance wake-up times by 30-min daily. Motivation ratings of desire, ability, reason, need and commitment to change sleep patterns were taken at baseline. Sleep diaries were taken at the end of treatment session 1, with sequentially earlier wake-up times in 30-min intervals indicating compliance. RESULTS At the outset of therapy, adolescents indicated strong desire, reasons and need, yet moderate ability and commitment to advance their sleep-wake patterns. Following therapy, sleep-onset times were significantly advanced, total sleep time increased and sleep latency decreased (all p < 0.05). Therapy lasted 6-27 days (M = 13.9 ± 4.5) and clients complied for approximately half the time (between 3 and 15 days; M = 8.8 ± 2.7). Commitment was associated with ability (r = 0.66, p < 0.001) but not desire, reason or need (all p > 0.05). Adolescents' desire to change (r = 0.30, p = 0.03) and commitment (r = 0.30, p = 0.03) were positively correlated with behaviour change, but their need, ability and reasons were not. A mediation analysis showed that ability and desire were important in predicting behaviour change, by total effects through commitment (ie, indirectly and directly). CONCLUSION Our findings suggest that the total effects of ability (ie, confidence) and desire to change are the best predictors of behavioural changes, thus clinicians should focus on these components of the readiness to change model when undertaking treatments with sleep-disordered adolescents.

STUDY OBJECTIVES Consumer sleep trackers issue daily guidance on 'readiness' without clear empirical basis. We investigated how self-rated mood, motivation, and sleepiness (MMS) levels are affected by daily fluctuations in sleep duration, timing, and efficiency and overall sleep regularity. We also determined how temporally specific these associations are. METHODS 119 healthy university students (64 female, mean age = 22.54 ± 1.74 years) wore a wearable sleep tracker and undertook twice-daily smartphone-delivered ecological momentary assessment of mood, motivation, and sleepiness at post-wake and pre-bedtime timings for 2-6 weeks. Naps and their duration were reported daily. Nocturnal sleep on 2471 nights were examined using multilevel models to uncover within-subject and between-subject associations between sleep duration, timing, efficiency, and nap duration on following day MMS ratings. Time-lagged analyses examined the temporal specificity of these associations. Linear regression models investigated associations between MMS ratings and sleep variability, controlling for sleep duration. RESULTS Nocturnal sleep durations were short (6.03 ± 0.71 h), and bedtimes were late (1:42AM ± 1:05). Within-subjects, nocturnal sleep longer than a person's average was associated with better mood, higher motivation, and lower sleepiness after waking. Effects of such longer sleep duration lingered for mood and sleepiness till the pre-bedtime window (all Ps < .005) but did not extend to the next day. Between-subjects, higher intraindividual sleep variability, but not sleep duration, was associated with poorer mood and lower motivation after waking. Longer average sleep duration was associated with less sleepiness after waking and lower motivation pre-bedtime (all Ps < .05). Longer naps reduced post-nap sleepiness and improved mood. Controlling for nocturnal sleep duration, longer naps also associated with lower post-waking sleepiness on the following day. CONCLUSIONS Positive connections between nocturnal sleep and nap duration with MMS are temporally circumscribed, lending credence to the construction of sleep-based, daily 'readiness' scores. Higher sleep duration variability lowers an individual's post waking mood and motivation. CLINICAL TRIAL ID ClinicalTrials.gov NCT04880629.

… Dark periods were for sleep when the body was at rest, and … dark, and patterns such as the sleep/wake cycle, daily patterns … by which light enters the body for non-visual effects, but it is …

… But we also learn that lighting during daytime hours can influence the sleep quality during … for non-visual biological effects, we are now able to start defining lighting situations that …

The use of adaptive lighting systems, which target an individual’s psychophysiological state, presents an opportunity to enhance employee’s health while simultaneously decreasing energy consumption. Although current studies show a significant increase in knowledge about the non-visual effects of lighting on individuals, no models or control algorithms have been developed for practical applications that utilize information about the influence of lighting on human states. To address this problem, a preliminary model was developed using both objective and subjective measures to determine individual psychophysiological states. A methodology was established to implement this model in office settings with computers operating for a standard 8‑hour workday. The model was tested in an office setting containing eight workspaces. In the first stage, both control and experimental groups were utilized. In the second stage of the testing, one group of participants took part. The correlated colour temperature ranged from 2700 K to 6100 K, while horizontal illuminance varied from 275 lx to 1060 lx. Electrical lighting control algorithms have been developed using psychophysiological state data. After two stages of full-scale modelling, the model was modified for simplicity and practicality. The results of this research indicate that adaptive lighting technology effectively enhances an individual’s psychophysiological state.

… This regulated rhythm benefits spatial memory by enhancing … Natural light also reduces stress and improves mood by … natural light, adopting adaptive artificial lighting systems, and …

… ease than those under cool lighting, a substantial difference from a design perspective. Therefore, the findings hold strong practical relevance for adaptive lighting strategies in co-…