Im looking for the the name of an anime i watched years ago....me and a freind were talking about it the other day but for the life of us we cant renember what it is called.

Basically this mechanical hospital bed is created to replace doctors. and they strap this old patient in it.The hospital bed then gains a consiunse and starts going on a rampage thru tokyo (with the old guy still in it) i also renember the army trying to stop it.(strange yes)

any ideas of the title? ive searched google but to no avail