Monitoring how long a user sleeps is an increasingly common feature in activity trackers, but Basis is upping the ante with a new suite of advanced analytics that can actually break down the phases of sleep users experience over the course of the night. Were getting at real physiological signals. The key to that trick is the devices array of sensors, which allow the device to determine when a user is sleeping, and its that same trove of data Basis is using for the new sleep analytics. Were getting at real physiological signals, says Basis CEO Jef Holove, which provide the companys algorithms the data they need to track the body with particular nuance.