<script>

    var time = new Date().getTime();

    var refreshTime = 6*1000;

    $(document).bind("blur focus focusin focusout load resize scroll unload click dblclick mousedown mouseup mousemove mouseover mouseout mouseenter mouseleave change select submit keydown keypress keyup error hover change", function(e) {

    time = new Date().getTime(); });

    function refresh()

    {

       if(new Date().getTime() - time >= refreshTime)

           window.location.reload(true);

       else

    setTimeout(refresh, refreshTime);    

      }

     setTimeout(refresh, refreshTime);

</script>

Current code is set for 6 sec...

In admin/settings/page

Add this little script to CUSTOM HEAD CODE.

Yes it does refresh the whole page but it will cancel /  Reset when many commands are done. Example : If the mouse is moved or a key is pressed it'll reset the trimer...