Circadian Lighting – Myth or Magic

Dr. James Mckenzie Fenella Frost

PhotonStar LED Group plc www.photonstarled.com

We evolved to thrive in dynamic natural light

The colour and intensity of light entrains our “circadian rhythm”

Positively effecting our bodies and minds throughout every day

Circadian Rhythms: Importance in People

• Sleep Patterns & Sleep Quality

• Eating patterns & habits

• Brainwave activity

• Hormone production

Disruption of the Circadian Rhythm

• Jet lag

• Fatigue

• Disorientation

• Insomnia

• Just a few examples.....

Light – The Ultimate Zeitgeber

• Introducing ipRGCs

• The SCN

• 460nM blue – the critical wavelength

• Aligns the Circadian Rhythm

“Timegiver” or external cue

Wout van Bommel 2003,

Spectral Sensitivity of ipRGCs

Blue Light MUST be at the correct time

A Good Nights Sleep

• Nursing Home : Night time amber lighting

– 83% had been woken up by lighting used at night

– With Amber – None woke up at night

Figueiro and Rea, 2005

Current Research: Health & Wellbeing

• General Health

• Weight control – and diabetes

• ADHD

• Dementia / Alzheimer's

• Cancers

• Cardiovascular Disease

• Longer Life

Mental Health & Behaviour

Studies show that use of dynamic lighting can:

•Improve attention

•Improve performance

•Improve behaviour

•Improve recovery times

•Improve symptoms for

Alzheimer sufferers

•Improve mood

A 2011 study using dynamic lighting in

schools documents

a reading speed increase of 35%,

concentration improves, thereby reducing

errors 45% and classroom hyperactivity is

reduced by 76%.

Emotional Effects

Van Bommel 2006

Circadian & Healthy Lighting

• Full Spectrum / High CRI

• Dynamic – right light at right time

• Ultimately daylight IS best

Technology Requirements for Circadian Lighting

• Aim is to be like the sun – dynamic, high CRI

• Colour tune to provide the right light at the right time – visually circa 2700K to 6500K

– People prefer “tropical” daylight to “polar”

– Correct blue content for time of day

• Do not need UV or IR

• Controls (time based) of intensity & CCT

Spectral Density

• Aim: to be close to daylight/sunlight

• Consider ratio of photopic range against circadian range

Circadian Lighting Solutions – Non LED

• SAD lamps

• Fluorescent

– 2 lamps with warm and cool CCTs

• Candle Light at Night

Circadian Lighting Solutions –LED

• RGB plus discreet additional colours

– colour rendering and stability issues

• 2 CCT LEDs (cool/warm)

– 460nm blue present in too high levels in warm white

• Advanced colour mix

– including PhotonStar ChromaWhiteTM

ChromaWhiteTM

• Advanced Colour Mix technology

• Spectrally closer to sunlight

• Excellent CRI & superb CGA

• Active stability with on board feedback loops

@4000K

• LumenLocTM

– Active Luminous Flux Stability & Control

• CRILocTM – Active Colour Quality Monitoring &

Control

• ColourLocTM – Active Colour Stability & Control

• ThermaLocTM – Active Thermal Monitoring and

Adaptive Protection

Embedded Technology for Stability & Control

ChromaWhiteTM Versions: Software Controlled

• VCCT Version for circadian lighting

• Other version examples

– Emulation of Conventional Sources • Tungsten+ - warms to 2400K when dimmed

• Specific lamp types

– Specific colours for food lighting • Including off black body

ChromaWhiteTM VCCT Version

• Tuneable 2700K to 6500K

• Ra >93 (R9>90)

• Active <3 MacAdam Ellipse Stability

ChromaWhiteTM Products

CLE Compact Light Engine Optimised for specular reflectors Up to 1000lm Compatible with multiple accessories

SLLE Spot Light Engine Optimised for reflectors High luminous flux up to 2500lm Compatible with multiple accessories

Additional Zhaga / industry standard light engine footprints will be added to complement existing fixed white solutions

Target Markets – Retail, Hospitality

Good colour rendering is essential for retail, hospitality and many other specialty applications (such as medical).

Poor colour rendering is a significant barrier to efficient sources being accepted in such environments.

Other Applications