If you want to learn more about what is possible the work of Dina Katabi is a good place to start:<p><a href="https://scholar.google.com/scholar?hl=en&as_sdt=0%2C44&q=dina+katabi&btnG=" rel="nofollow">https://scholar.google.com/scholar?hl=en&as_sdt=0%2C44&q=din...</a><p><a href="https://www.csail.mit.edu/person/dina-katabi" rel="nofollow">https://www.csail.mit.edu/person/dina-katabi</a><p>Body tracking through walls, monitoring breathing and heart rate, through wall human pose estimation, multiperson localization, virtual touch screen. The latest work of her group is on emotion recognition using WiFi:<p><a href="https://www.csail.mit.edu/research/eq-radio-emotion-recognition-using-wireless-signals" rel="nofollow">https://www.csail.mit.edu/research/eq-radio-emotion-recognit...</a>