A range of sensors to detect when a person begins to wander.
"Which sensor should I choose?"
This largely depends on what you are trying to achieve and how quickly you need to be alerted.
I need to know as soon as a person gets out of bed, so that I can prevent them from falling.
A bed pressure mat provides the fastest early warning that a person has left the bed.
Alternatively, a floor sensor mat can be placed next to the bed.
I need to know if a person moves through a doorway
If the door is normally kept closed, a door sensor will alert the pager as soon as a door is opened.
If the door is sometimes open, a motion sensor can be positioned to detect movement through the doorway. This could be wall mounted or simply placed on a shelf.
I am not at home and need to know if a person leaves the house
A door alarm connected to your home Wifi will send a message to your mobile phone if the front door is opened.