Spinoff is NASA’s annual publication featuring successfully commercialized NASA technology. This commercialization has contributed to the development of products and services in the fields of health and medicine, consumer goods, transportation, public safety, computer technology, and environmental resources.
In 2016, a National Sleep Foundation survey found that 3 percent of American adults — amounting to more than 7 million drivers — had dozed off behind the wheel during the two weeks before the survey. Many factors contribute to sleeplessness, but researchers are finding that a major one is light exposure — and not just the amount of light we’re exposed to, but the color of the light.
Fares Siddiqui was surprised when an acquaintance mentioned this to him in late 2015. He immediately did some research and found a 2007 study demonstrating that in addition to image-forming rods and cones, the human eye has a third type of photoreceptor that influences circadian rhythms, now known as the intrinsically photosensitive retinal ganglion cell.
The study showed that even in blind subjects, exposure to short-wavelength blue light suppressed melatonin, causing alertness, while light at the longer wavelengths where visual sensitivity peaks, did not. These blue wavelengths are abundant in daylight, and their suppression of melatonin causes a reset of the circadian rhythm that governs sleep and wakefulness.
Prior to this study, in 1990, NASA had reached out to Charles Czeisler, then an associate professor at Harvard Medical School and a specialist in circadian rhythms, who had just demonstrated the ability to reset the circadian clocks of night-shift workers by systematically exposing them to light. At the time, astronauts preparing for a nighttime shuttle launch that kept getting postponed were having a hard time adjusting to their inverted schedule. Czeisler repeated his experiment on the crew with success.
Since about 2000, the NASA-funded National Space Biomedical Research Institute (NSBRI) has collaborated with Harvard Medical School, Brigham and Women’s Hospital, Thomas Jefferson University, and others in numerous studies to advance understanding of light’s influence on circadian rhythms, culminating in the delivery of tunable LED lighting modules to the International Space Station (ISS) in late 2016. NASA has a keen interest in the subject because sleep is problematic for astronauts on the ISS, which sees 15 or 16 sunrises and sunsets every 24 hours, and no space travelers experience the normal 24-hour Earth day.
Based on research, Siddiqui knew when he founded Circadia, based in London and San Francisco, that his product would need a tunable LED lamp akin to the ones going to the ISS. But he wanted to take the concept a step further, basing light exposure on individual sleeping patterns. To determine these sleep patterns, he settled on con-tactless radar-based technology to create a device that mounts on the wall or ceiling in the vicinity of the user’s bed, and can detect the rise and fall of a sleeper’s chest — as well as the intensity of movement during sleep — from up to eight feet away. With the help of Circadia’s proprietary machine-learning algorithms, the sleep tracker can use this data to determine with 92 percent accuracy what stage of sleep the user is in.
Sleep-stage data is in turn fed into a smartphone app based on software that Harvard Medical School and Brigham and Women’s Hospital created in part with funding both directly from NASA and from the NSBRI. The app provides the link between the sleep tracker and a portable light therapy device that sits on a desk to provide what Siddiqui calls “visual caffeine” throughout the day.
This is primarily light in the short, blue wavelengths that retinal ganglion cells respond to by suppressing melatonin production. The idea is to induce wakefulness during the day to promote sleepiness at night. Then, in the hours before bedtime, longer-wavelength reddish light simulates late evening light and stops preventing the hormone’s production.
What sets Circadia’s system apart from any other light therapy or sleep tracker it that it combines diagnostics and treatment in one complete, closed-loop system. The app links the sleep tracking and light therapy devices, calculating and adjusting the wavelengths, intensities, and durations of light exposure throughout the day based on nighttime sleep patterns. The sleep tracker also takes into account environmental factors that can affect quality of sleep such as temperature, humidity, and light.
Circadia took its product to Kick-starter in June of 2017, accepting orders for the paired sleep tracker and light therapy device, although Siddiqui says the devices will also be offered separately in the future. Those orders are scheduled to ship this year.
In addition to helping users maintain a steady, healthy sleep cycle, Circadia’s system can also retrain circadian rhythms — much as Czeisler did for the Space Shuttle crew almost three decades ago — whether that’s to adjust to shift work, get to bed earlier, or overcome jet lag.