Then, one night about two years ago, I was looking after my grandfather and I saw him stepping out of the bed. The moment his foot landed on the floor, I thought, why don't I put a pressure sensor on the heel of his foot? Once he stepped onto the floor and out of the bed, the pressure sensor would detect an increase in pressure caused by body weight and then wirelessly send an audible alert to the caregiver's smartphone. That way, my aunt could sleep much better at night without having to worry about my grandfather's wandering.