I could never find information readily available on how sleep actigraphy actually works, but nearly each time someone sees me wearing the Jawbone UP it inevitably becomes a conversation topic and “witchcraft” doesn’t cut it. So after reading a few medical papers (thanks Stanford Library), here’s what I’ve distilled:
What the devil is actigraphy?
Actigraphy is the use of accelerometers (motion trackers) to monitor physical activity, whether waking life or sleep. Pilots, medical professionals, and militaries have used it extensively for decades, and in more recent years increasing numbers of consumer products have been released. The most simple example is a pedometer, and more complex devices include the WakeMate, FitBit, and Jawbone UP. Even some apps will turn your Smartphone into an actigraphy device.
Use of actigraphy for sleep seeded in the 1960s when predictable limb activity was discovered during sleep studies. It was found that wearing an actigraphic device on a person’s non-dominant wrist was actually just about as accurate as more disruptive forms of tracking sleep such as attaching electrodes to your skull. But how is that possible? What is your wrist up to that allows a relatively simple gadget to match the accuracy of machines that measure your brainwaves? Continue reading
Immediately following the 3G iPhone announcement at 11:45a PST this morning, AT&T posted up a 
