This is the kind of future tech that seems like it should still be in sci-fi. Instead of an embedded chip/machine like we normally expect in "wearables," this is a fiber running through the entire thing that's so thin it's basically imperceptible and can survive machine washing.

Mind you, given the current state of surveillance tech, I'm not sure I want any clothing that tracks my vitals unless I can control exactly where that info goes (and doesn't go), but I do find the concept really nifty.