If you suffer from sleep disorders, or know anyone who does, then you have definitely heard of the complex process they have to go through to assess the level of sleep depravity they suffer from. Not only that, but also needs to be strapped to a complex array of sensors that monitor brain activity, muscle activity, eye movement, and heart and breathing rate. Nyx Devices has developed a nightshirt that is embedded with fabric electronics to monitor the wearer's breathing patterns. A small chip worn in a pocket of the shirt processes that data to determine the phase of sleep, such as REM sleep (when we dream), light sleep, or deep sleep.
"It has no adhesive and doesn't need any special setup to wear," says Matt Bianchi, a sleep neurologist at Massachusetts General Hospital and co-inventor of the shirt with Carson Darling, Pablo Bello, and Thomas Lipoma. "It's very easy—you just slip it on at night," says Bianchi, who has no formal role with Nyx Devices. Nyx's Somnus shirt dramatically simplifies this by focusing only on respiration. "It turns out that you can tell if someone is awake or asleep and which stage of sleep they are in purely based on breathing pattern," says Bianchi. "That's a much easier signal to analyze than electrical activity from the brain."
During REM sleep, the respiratory pattern is irregular, with differences in the size of breaths and the spacing between them. Breathing during deep sleep follows an ordered pattern, "like a sine wave," says Bianchi. "And the breath-to-breath differences are very small." The lighter stages of non-REM sleep fall somewhere in between. "The motivation behind the shirt is to allow repeated measurements over time in the home," he adds. Analyzing sleep stages based on respiration is still considered experimental. But Bianchi is now testing the device on patients who come to his sleep clinic who are also assessed using standard technology, known as polysomnography. The team will soon begin home tests of the shirts to further validate its use outside of the lab. The company hopes to have a commercial product available by summer of 2012 for less than $100.
Doctors now can put an array of electrodes on the surface of the brain to pinpoint the source of epileptic seizures. Thin, flexible electrodes mounted on top of a biodegradable silk substrate could provide a better brain-machine interface. The device wraps around the crevices in the surface of the brain. These neural interfaces take higher-resolution measurements than what's available today without irritating or scarring brain tissue. It has shown substantial results and technical accomplishments on cats.
