CMU researchers show potential of privacy-preserving activity tracking using radar

Imagine if you could settle/rekindle domestic arguments by asking your smart speaker when the room last got cleaned or whether the bins already got taken out?
Or — for an altogether healthier use-case — what if you could ask your speaker to keep count of reps as you do squats and bench presses? Or switch into full-on ‘personal trainer’ mode — barking orders to peddle faster as you spin cycles on a dusty old exercise bike (who needs a Peloton!).
And what if the speak