Motion Sensor Alert (not loud alarm)

My stepfather is on hospice for cancer, and extremely weak, and we're having some issues getting him to rely more on us for help, as he's a very independent person. Long story short, we need to find a solution that doesn't involve an action on his part to alert us that he needs something, such as to get up for the bathroom or whatever. He's in danger of hurting himself, among other things, because half the time he refuses to attempt to alert us himself.

Does anyone have any experience with a good motion sensing alert system? Ideally a sensor would sense his movement, and then alert via a FOB or something placed elsewhere (i.e. the alert noise/vibration whatever wouldn't be located in his room). I'm sure what I'm looking for exists, for small children and such, I just don't know where to look to find exactly what I need.