This is indeed an awesome area that I’ve barely ever considered. If I had to go do another PhD, it might be in this. I’ve seen research about using cell phones

This is indeed an awesome area that I’ve barely ever considered. If I had to go do another PhD, it might be in this. I’ve seen research about using cell phones to detect drug use (and try to prevent the urge). What other everyday objects could be utilized? What about my phone’s front facing camera to scan my face looking for muscle twitches or eye issues?