Light & Health - Design Strategies & Technologies April 17, 2014 Konstantinos Papamichael, Ph.D. Professor, Design Program, College of Letters & Science 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
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Sun
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Spectral Distribution of Sunlight
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The Electromagnetic Spectrum
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Daylight Spectral Power Distributions
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The Dynamic Nature of Daylight
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Photopic & Scotopic Sensitivities
http://www.handprint.com/HP/WCL/color1.html
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The CCT of Daylight
http://www.lrc.rpi.edu/programs/nlpip/lightinganswers/fullspectrum/comparisons.asp 9
Human Evolution - Sunrise
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Human Evolution - Daytime
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Human Evolution - Sunset
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Evolution - Night
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Evolution - Light at Night
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Evolution - Light at Night
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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!
Pupil!
Vitreous Humor!
Eyelens!
Fovea! Retina! Optic Nerve!
Cornea! Aqueous Humor! Suspensory ligament!
Choroid! 17
Retinal Structure
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Rods & Cones
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Photopic & Scotopic Sensitivities
http://www.handprint.com/HP/WCL/color1.html
http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html 20
Photopic & Scotopic Sensitivities
https://www.rasc.ca/technology
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ipRGC - Melanopsin intrinsically photosensitive Retinal Ganglion Cell
• • • •
•Specialized Photo pigment ganglion cell •Melanopsin Specialized photopigent ganglion cells Biological path
• Biological path Circadian Rythms
• Circadian rhythms •
Pupilary control
• Pupillary reflex
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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%
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Neural change: changing synaptic interaction – Lower overall neural sensitivity as light level increases – Factor of about 1000%
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Photopic, Scotopic & Circadian Sensitivities
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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 – ...
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Melatonin & Cortisol Circadian Rhythms
Incandescent Spectral Power Distribution
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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
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Fluorescent Lighting CCT (K) 2700
3000
3100
3500
3500
4100
5000
6500
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Fluorescent Spectral Power Distribution
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Spectral Power Distributions
Natural Daylight
Cool White Fluorescent
Tri-Phosphor 3500K
Incandescent
Daylight Fluorescent
Metal Halide 31
UC Davis Medical Center Sign
Photopic Illuminance: 2 fc - Scotopic Illuminance: 200+ fc 32
Photopic, Scotopic & Cirtopic Lumens
?
200
2 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 socie5es acquire technology and expand industry. Among the la;er (health effects) are poten5al carcinogenic effects related to melatonin suppression, especially breast cancer. Other diseases that may be exacerbated by circadian disrup5on 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 occupa5onal and environmental exposure to light -‐at-‐night, the risk of cancer, and effects on various chronic diseases. 34
Blue-rich LED & Circadian Sensitivity
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Key Lighting Design Strategy 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
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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.
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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%)
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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
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Monochromatic LED Spectra Manufacturer A 400
550 446
477
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Monochromatic LED Spectra Manufacturer B
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Bathroom Light Switch with Occupancy Sensor & Amber LED Night Light
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Dual Source Bi-level Outdoor Luminaire Amber LED & Induction Lighting
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Dual Source Bi-level Outdoor Luminaire Occupancy Mode
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Dual Source Bi-level Outdoor Luminaire Vacancy Mode
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Indirect Downlight Prototypes
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Dual Source Kitchen Lighting Full Light Output
Night Lighting - Amber LEDs
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Honda House - First Floor Amber LED Way Finding Night Lighting
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Honda House - Second Floor Amber LED Way Finding Night Lighting
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Bathroom & Kitchen Lighting
Amber LED “Toe-Kick” Night Light
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Amber LED “Toe-Kick” Night Light
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Kitchen High & Low Amber LED Night Light
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Kitchen Amber LED Night Lighting
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Kitchen Lighting...
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Bedroom Lighting...
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Living Room - High & Low Ambient Lighting
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Stairwell & Corridor Night Lighting
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Bathroom Night Light
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Corridor Night Light
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Maximizing Health & Sleep in the Elderly LD+A Article by Kimberly Mercier
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Circadian Lighting for Assisted Living
h;p://www.rzb.de/en/company/press/press-‐releases/ar5cle/light-‐health-‐circadian-‐ligh5ng/ h;p://objects.designapplause.com/wp-‐content/xxG58hlz9/2012/11/econe-‐2.png 62
Philips "Hue" Screw-based Lamp
DigitalTrends.com
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Wireless Base - Hardwired to Wi-Fi Router
DigitalTrends.com
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“Relax” Setting
DigitalTrends.com
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“Concentrate” Setting
DigitalTrends.com
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“Reading” Setting
DigitalTrends.com
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Philips "Hue" Screw-based Lamps
DigitalTrends.com
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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 Ac5vity 3000K -‐ Relax Photo credit: Philips
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Spectrally Tunable Lighting for Office Spaces
– Intensity – CCT
• •
NEUTRAL
Laboratory Prototype Independent control of
Change CCT maintaining Intensity Change intensity maintaining CCT
COOL
• •
WARM
100%
50%
25%
Thank You! Questions?
[email protected]
RESEARCH
INNOVATION
PARTNERSHIP
633 Pena Drive, Davis, CA, 95618 | cltc.ucdavis.edu | PH: 530-747-3838, FAX:530-747-3812
