The Lighting Research Center at Rensselaer Polytechnic Institute is forming a collaborative group of researchers from around the world to collect data in different lighting applications using a special light measuring device called the Daysimeter. The group’s goal is to create a cooperative forum of manufacturers, scholars, scientists, and physicians who are already working in clinical applications and work environments where photobiology and circadian light exposure could be important for health and productivity.
“The human circadian system responds to light in a dramatically different manner than the visual system,” explained Mark Rea, PhD, the director of the LRC. “Light is the main stimulus that affects the human body’s clock; circadian rhythms keep the body synchronized with the solar day.”
Studies have shown that light impacts people’s health and well-being. However, it has been nearly impossible to measure a person’s quantity and quality of circadian light exposure accurately—until now. The group will measure circadian light exposure with the Daysimeter, a field research tool developed by the LRC. The Daysimeter is the first device to characterize light accurately by measuring spectrally weighted intensity, as well as timing and duration, of circadian light entering the eye, which affects the human body’s clock. Lightweight and easy to wear, the device also measures conventional light levels and records head movements in order to differentiate between rest/sleep periods and active/awake periods.
Ultimately, the Daysimeter will enable the design of light sources, luminaires (light fixtures), and lighting techniques that help people to maintain regular circadian functions such as the sleep/wake cycle and hormone production, explained Rea. This, in turn, may improve their health.
The LRC will explore clinical and special applications in which people could benefit from lighting specially tuned to the circadian system. These include hospitals, intensive care units, and assisted care facilities where patients do not have regular exposure to daylight or darkness, as well as work environments that do not allow for customary light and dark exposures such as some military operations. </div>
"The work of the Daysimeter User Group may lead to a better understanding of many health-related issues,” said Rea. He went on to explain that those issues include: how premature infants develop; appropriate learning environments for school children; improved sleep for people with Alzheimer’s disease and their at-home caregivers; teenagers with delayed sleep phase disorder; and biophysical and epidemiological concerns for senior-care residents, night-shift workers, travelers with jet lag, and others with altered light-dark exposures and sleep patterns.
As part of the Daysimeter User Group, the LRC will participate in establishing a common protocol for the use of the Daysimeter. LRC scientists will also conduct research, demonstration, evaluation, and educational activities related to its use. The first meeting of the Daysimeter User Group is scheduled for March 7, 2007, at the LRC in Troy, N.Y. Interested parties can contact Patricia Rizzo at 518-687-7100 or firstname.lastname@example.org.
More about the Daysimeter and measuring circadian light
Larger versions of this and other related photos are available upon request.</div>
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