Time out page if looses focus

Time out page if looses focus


Hi,
I am working on a html5 app that displays medical information using jQuery Mobile. To be compliant to medical standards the information on the page needs to "go away" if the user leaves the page.  So no one can pick up the phone and view someones medical info.
What we want is if the user leaves the page and comes back in say 30 seconds the page stays. After longer than 30 seconds we load a blank page.
I tried using window.blur and window.onfocus and it works great in chrome on windows 7, but seems to be ignored on mobile devices.

Does anyone have experience with this sort of thing and can point me in some direction?

Thanks