US scientists have developed a special tool to help designers create lighting installations which affect the sleep-wake cycle.
Using a free calculator, lighting professionals can specify the right light sources and light levels to stimulate the so-called ‘circadian’ rhythm of building occupants.
The researchers – based at the Lighting Research Center at Rensselaer Polytechnic Institute in New York state – have worked out the type of lighting needed to influence the body’s biochemistry.
Dubbed the circadian stimulus – or CS – metric, this is the type and intensity of the lighting needed to suppress the hormones that make us feel sleepy.
‘Lighting for the circadian system employs lighting design objectives that differ from those typically used in traditional architectural lighting design, and therefore, requires metrics that differ from those currently used by lighting designers,’ Professor Mariana Figueiro, Light and Health Program Director at the LRC, told Lux.
The CS metric is based on the scientists’ model of how the retina converts light signals into neural signals for the circadian system. Specifically, it identifies the lighting needed to suppress the sleep hormone melatonin.
When specifying lighting for the circadian system, the LRC says it’s important to consider light level, spectral composition, timing and duration of the exposure, and the previous light exposures of the occupants.
We have recently upgraded our spectrometer to reveal on light test the CS metric as well as the Human Photopigment calculator