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Light & Health 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 • •Circadian Circadian Rhythms rhythms • •Pupillary Pupillary (+?) 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 Polluon: Adverse Health Effects of Nigh;me Lighng Report 4 of the Council on Science and Public Health (A-12) of the American Medical Associaon 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 sociees acquire technology and expand industry. Among the la;er (health effects) are potenal carcinogenic effects related to melatonin suppression, especially breast cancer. Other diseases that may be exacerbated by circadian disrupon 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 muldisciplinary research on occupaonal 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 Acvity 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 .
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