We're using the pressure mat sold by Amazon for my dad, because he's started wandering out at night. We've placed it at his front door, so when he stands on it to go out of the door the alarm goes off in our house (we live next door). The first one we ordered was defective, but there was no problem replacing it. It can also be used to alert you when somebody gets out of bed, but I've no idea whether it would work with the kind of mattress you're talking about I'm afraid. Hope this is a bit of help.