Light & Health - Design Strategies & Technologies
February 12, 2015
Konstantinos Papamichael, Ph.D. Professor, Department of Design Co-Director, California Lighting Technology Center University of California, Davis
RESEARCH INNOVATION PARTNERSHIP 633 Pena Drive, Davis, CA, 95618 | cltc.ucdavis.edu | PH: 530-747-3838, FAX:530-747-3812 The Main Source of Light & Life
2 The Sun
3 Spectral Distribution of Sunlight
4 The Electromagnetic Spectrum
5 Daylight Spectral Power Distributions
6 The Dynamic Nature of Daylight
7 Daylight Spectral Power Distributions
http://www.handprint.com/HP/WCL/color1.html 8 Daylight Correlated Color Temperature (CCT)
http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/fullspectrum/comparisons.asp
9 Human Evolution - Sunrise
10 Human Evolution - Daytime
11 Human Evolution - Sunset
12 Human Evolution - Night
13 Human Evolution - Light at Night
14 Human Evolution - Light at Night
15 Visual & Circadian Pathways
1. Visual Pathway
– Light stimulates the cerebral cortex for vision & perception
2. Biological Pathway
– Light causes messages along a biological pathway (Hypothalamus, Pituitary, Pineal Gland) that are used to regulate the body’s autonomic nervous and endocrine systems
16 Human Eye Anatomy
Ciliary Muscle! Sclera!
Iris! Vitreous Humor!
Fovea! Pupil! Eyelens! Retina!
Optic Nerve! Cornea! Aqueous Humor!
Suspensory ligament! Choroid!
17 Retinal Structure
18 Rods (Rhodopsin) & Cones (Photopsins)
19 Photopsin & Rhodopsin Sensitivities
http://www.handprint.com/HP/WCL/color1.html http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html
20 ipRGC (Melanopsin) intrinsically photosensitive Retinal Ganglion Cell
• • SpecializedPhoto pigment ganglion cell • • ManySpecialized & long tentacles • Melanopsinganglion photopigm cells ent
• • BiologicalBiological path path
• • CircadianCircadian Rhythms rhythms
• • PupillaryPupillary (+?) reflexcontrol
21 Adaptation Mechanisms
• Mechanical change: pupil diameter
– Admits varying amounts of light – Factor of about 5% • Photochemical change: changing amounts of photo pigments available
– Bleaching makes less pigment available – Factor of about 1000% • Neural change: changing synaptic interaction
– Lower overall neural sensitivity as light level increases – Factor of about 1000%
22 Photopic, Scotopic & Circadian Sensitivities
23 Circadian Rhythms
• Endogenous (self-sustained) rhythms • From the Latin – “circa” = approximately – “dies” = day • Have been observed even in single celled organisms including prokaryotes, e.g,. bacteria • Major Biological Effects – Hormone Excretion • Melatonin - sleep-wake cycle • Insulin - carbohydrate metabolism • Cortisol - blood pressure & sugar levels – Body Temperature – Cognitive performance – ...
24 Melatonin & Cortisol Circadian Rhythms Incandescent Spectral Power Distribution
26 Pros & Cons of Incandescent Lighting
• Pros – Excellent color rendering - 100 CRI – Excellent for well-being & health - low blue content – Excellent dimming - smooth, further reducing blue content – Excellent drama - sharp shadows – No flicker! – No noise! – Low cost
• Cons – Low luminous efficacy
27 Fluorescent Lighting CCT (K)
2700 3000 3100 3500
3500 4100 5000 6500
28 Fluorescent Spectral Power Distribution
29 Spectral Power Distributions
Natural Daylight Cool White Fluorescent Tri-Phosphor 3500K
Incandescent Daylight Fluorescent Metal Halide
30 UC Davis Medical Center Sign
Photopic Illuminance: 2 fc - Scotopic Illuminance: 200+ fc
31 Photopic, Scotopic & …Cirtopic? Lumens
?
200
2
32 Blue-rich Light at Night
33 American Medical Association - June 2012
Light Pollu on: Adverse Health Effects of Nigh me Ligh ng Report 4 of the Council on Science and Public Health (A-12) of the American Medical Associa on
Biological adapta on to the sun has evolved over billions of years.
The power to ar ficially override the natural cycle of light and dark is a recent event and represents a man-made self-experiment on the effects of exposure to increasingly bright light during the night as human socie es acquire technology and expand industry.
Among the la er (health effects) are poten al carcinogenic effects related to melatonin suppression, especially breast cancer. Other diseases that may be exacerbated by circadian disrup on include obesity, diabetes, depression and mood disorders, and reproduc ve problems.
Due to the nearly ubiquitous exposure to light at inappropriate mes rela ve to endogenous circadian rhythms, a need exists for further mul disciplinary research on occupa onal and environmental exposure to light -at-night, the 34 Blue-rich LED & Circadian Sensitivity
35 Key Lighting Design Strategies for Health
• Reduce exposure to blue light during the night – Outdoor lighting • Luminaires • Signage – Indoor lighting - especially residential • Luminaires • Televisions • Computer displays • Increase exposure to blue light during the day – Daylight! – High CCT light sources for applications that need it • Offices • Schools • Work spaces • Assisted living housing
36 Implementation Strategies & Technologies
• Outdoor Lighting – Occupancy-based bi-level lighting • Single Source – Full output during occupancy – 50% or less during vacancy (10% - 20% is enough) • Dual Source – High level Low CCT white light during occupancy – Low level Amber or Amber-Red LED during vacancy • Indoor Lighting – Nighttime • Low CCT (less than 3,000k) • Low level Amber or Amber-Red LED for nightlight – Kitchen – Bathroom – Way finding – Daytime • Daylight! • High CCT lighting - for applications that need it
37 High CCT Lighting for Offices & Schools
• Mills, Peter R., Tomkins, Susannah C. and Schlangen, Luc JM. “The effect of high correlated colour temperature office lighting on employee wellbeing and work performance.” Journal of Circadian Rhythms, 11 January 2007, pages 2-5.
• High CCT Electric Lighting in Call Center with Shift Work
• Reduced fatigue (26.9%) • Increased alertness (28.2%) • Reduced daytime sleepiness (31%) • Increased work performance (19.4%) • Increased vitality (28.4%) • Increased mental health (13.9%)
38 Melatonin Suppression
Brainard, George C. “Action Spectrum for Melatonin Regulation in Humans: Evidence for a Novel Circadian Photoreceptor.” The Journal of Neuroscience (2001): 6405-411. Web. 29 Apr. 2013.
446 477
39 Monochromatic LED Spectra Manufacturer A
400 550
446 477
40 Monochromatic LED Spectra Manufacturer B
Effective 400 550
Most Effective 446 477
41 Bathroom Light Switch with Occupancy Sensor & Amber LED Night Light
42 Dual Source Bi-level Outdoor Luminaire
Amber LED & Induction Lighting
43 Dual Source Bi-level Outdoor Luminaire
Occupancy Mode
44 Dual Source Bi-level Outdoor Luminaire
Vacancy Mode
45 Indirect Downlight Prototypes
46 Dual Source Kitchen Lighting
Full Light Output Night Lighting - Amber LEDs
47 100% 50% 25% Spectrally Tunable Lighting for Office Spaces WARM
• Laboratory Prototype • Independent control of – Intensity – CCT NEUTRAL
• Change CCT maintaining Intensity • Change intensity maintaining CCT COOL Refrigerator Lighting
White Light Amber Light 49 HONDA ZNE House, UC Davis
50 Honda House - First Floor Amber LED Way Finding Night Lighting
51 Honda House - Second Floor Amber LED Way Finding Night Lighting
52 Bathroom & Kitchen Lighting Amber LED “Toe-Kick” Night Light
54 Amber LED “Toe-Kick” Night Light
55 Kitchen Amber LED Night Lighting
56 Kitchen High & Low Amber LED Night Light
57 Living Room - High & Low Ambient Lighting
58 Corridor Lighting
59 Stairwell & Corridor Night Lighting
60 De Young ZNE House, Fresno, CA
61 Bathroom Lighting
62 Kitchen Lighting
63 Corridor Lighting
64 Maximizing Health & Sleep in the Elderly LD+A Article by Kimberly Mercier
65 Philips “Heu” Screw-based Lamp
DigitalTrends.com 66 Wireless Base - Hardwired to Wi-Fi Router
DigitalTrends.com 67 “Relax” Setting
DigitalTrends.com 68 “Concentrate” Setting
DigitalTrends.com 69 “Reading” Setting
DigitalTrends.com 70 Philips “Hue” Screw-based Lamps
DigitalTrends.com 71 Philips Circadian Lighting for Classrooms
12000K, 65fc average 6000K, 100fc average 3500K, 50fc average 2900K, 50fc average
5000K - Focus/Concentrate 6500K - Wake Up/Morning 4000K - Group Ac vity 3000K - Relax
Photo credit: Philips 72 Samjin Color-Tunable Lighting SAMJIN
100% BRIGHTNESS
50%
2700K 4000K 6500K
CCT 73 74 Thank You! [email protected]
RESEARCH INNOVATION PARTNERSHIP 633 Pena Drive, Davis, CA, 95618 | cltc.ucdavis.edu | PH: 530-747-3838, FAX:530-747-3812