MIT's CSAIL lab has just taken its very cool but kinda creepy WiFi motion tracking to a new level: monitoring your vital signs from another room. Last we saw, the same researchers bounced low-powered WiFi signals (100x less than a home router) off of individuals to finely track their position behind a wall. The resulting 10cm (four inch) precision was nothing compared to what they can now do, however. Fancier algorithms enabled the system to approximate subjects' volumes within millimeters, and then calculate their breathing level by amplifying and observing the subtle changes over time. From breathing levels, the researchers could extrapolate heart rate with 99 percent accuracy -- something foreshadowed uncannily by earlier research. The tech may lead to non-invasive vital sign monitoring, more advanced baby monitors and other, more sinister, applications.