He sleeps in a queen size bed and sleeps most of the day and all night long. My mom also has dementia and is trying to care for him as best she can. They both can use shower, toilet on own at this point. She trys to encourage him to sleep in the center of the bed but isn't always there while he is napping.
But I doubt another elder could manage all the bending, lifting & moving a crash mat. Probably then be a tripping hazzard for both.
A floor lowered bed is expensive & would either of them be able to use it appropritely? Probably not.
Bed sticks are out of favour. Too many accidents.
Some people stay on the edge as they can't move over well or get back again.
I'm sorry I can't think of anything! Just problems with the usual remedies. First do no harm comes to mind & if it ain't broke don't fix it.
I do sympathize... My sister does same & has rolled out multi times. No OT or Physio has been able to improve.
A "pool noodle" might also work.
Putting a long body pillow up against him might work as well.
Since this in their home you could also get one of the guard rails that you can attack. Place it at the top part of the bed just position it so that he can sit up and use the rail to hold onto as he gets up but the placement will hinder him from rolling off the edge.
If none of these works placing a mattress on the floor would be an option. If he were to roll off the mattress would cushion any fall. But it will make getting out of bed difficult and a possible trip hazard.
Lastly replacing the bed with a Hospital bed that can be raised and lowered and also using the guard rails. (can be done in a home setting where there are not the restrictions you would have in a facility)