This is incredible stuff! One of the less-hyped slow revolution is what's happening in non-wearable sensing. Some of it is driven by the consumer-ization of advanced radar systems, a technology that was the domain of the military and space/satellite comm.
Some companions to this work:
1. Wifi sensing from academia, particularly in the ubiquitous computing community- Shwetak Patel's group in Washington [1], Dina Katabi's group in MIT [2], Patwari's group in Utah [3], etc.
[4] I use 'advanced' in the sense that it is way, way, more sophisticated in its use of math and signal processing/machine learning/linear algebra algorithms than your standard automotive speed monitoring radar.