With a watch over sensor, a caregiver could monitor the recipient's behavior with the silhouette images, respecting his privacy and preventing from falling down from the bed or leaving out of the bed. The caregivers can determine the priority of their support when they are understaffed, bringing the good result of relieving the burden of caregivers. Also, since the caregivers can easily relocate the sensor, they can change the rooms to observe according to the situation. Watch Over Monitor is a