The device used microphones and speakers to detect movement of fingers. (pocket-lint.com)
When he became unable to move his hands sufficiently to use the switch, he moved to an infrared system mounted on his glasses, which detects movement in his cheek muscle. (newscientist.com)
If the sensor detects no movement from your baby after 20 seconds, you will receive an alert to give you the opportunity to check on your baby's safety. (omaby.com)