Hospital bed mattress/sleep number mattress

My son has now been moved to a hospital bed at home. And he’s been sleeping on a sleep number bed for the last six years. Unfortunately the hospital bed is very uncomfortable. I’ve tried toppers and mattress pads. But it’s still uncomfortable for him due to tumors on the spine. He likes the comfort of sinking in with sleep number mattress. So I’m looking for ideas of what mattress would compare to a sleep number mattress that would also work for an adjustable Hospital bed.