Gadget Predicts Proper Light Exposure, Could Solve Sleep Problems

The human body runs on a tight schedule of night and day. Going to work bright and early and clocking out when gets dark. Its not wonder the typical American's day is rife with yawns and grogginess; we're all not getting enough of that crucial light that keeps our brains in check. Now, a team of researchers at Rensselaer University are developing a personal device to measure daily light intake and activity, allowing them to predict the best time for light therapy and get their internal clocks in sync to the 24 hour day.

In short, they're creating a gadget that helps people "Lighten Up".

Sparse or irregular light exposure - something most individuals face on a regular basis - can cause circadian rhythm disruptions. Research has shown that light has an impact on everything from brain activity to seasonal depression and even increase the length and quality of sleep.

Supported by a $1.8 million grant from the National Institutes of Health, researchers in Rensselaer Polytechnic Institute's Lighting Research Center (LRC) are developing the Daysimeter, a small, head-mounted device to measure an individual's daily rest and activity patterns, and exposure to circadian light - short-wavelength light, particularly natural light from the blue sky, that stimulates the circadian system.

Like a clock that needs to be set for accurate time telling, the circadian clock - a brain based regulating mechanism that controls your body temperature, hormone production, sleep and wake patterns - requires "setting" from the light each day. Very bright days and very dark nights are the perfect regulator for the human circadian system but patterns of light and dark in today's modern world are inconsistent with the natural cycle.

Electricity has dramatically changed our light and dark exposure patterns, and indoor lighting can be insufficient to stimulate the circadian clock, according to Mark Rea, director of the LRC and principal investigator on the project. Exposure to indoor sources of light including computer screens, are usually too bright or seen for too long, offsetting the proper timing of the circadian clock. These disruptions can actually desynchronize the circadian rhythm from the natural solar daytime/nighttime cycle, leading to sleep problems and serious psychological stress such as mood disorders and depression.

Outdoor light levels during the day, even those under cloud cover or during the winter are of much higher levels than those found in windowless, artificially lit buildings. The absence of suitable light may induce 'circadian darkness' which brings on a plethora of problems.

If an individual's circadian light intake is deficient during the waking hours, the Daysimeter device will be able to reliably predict the light therapy necessary to resynchronize the circadian phase with the solar day.

Once completed, the device has the potential to help the lives of millions who suffer from sleep disorders. Including groups infamous for whacky schedules like College students, international business travelers and night time shift workers; who challenge their circadian rhythms every day.

Lighting Research Center
Circadian Research Findings
Links to Journals and Articles on Circadian Research