The Wake-up Angel pictured to the left is an "ear alarm" that vibrates to wake you up if you happen to fall asleep when you really shouldn't (like when driving or studying):
You place it behind the ear and if your head angle turns 30 degrees or lower, the Wake-up Angel will vibrate. There are four different levels to adjust at what angle the vibrator should be activated.
how about one that reads how closed your eyes are and if they get too droopy it sticks a load of pins in you