They are not trying to patent what's shown in the figures, those are just given as background information. A patent for a screwdriver will most certainly also d

They are not trying to patent what's shown in the figures, those are just given as background information. A patent for a screwdriver will most certainly also describe screws, regardless of whether screws are prior art. Patentability is solely a matter of the claims made at the end. Those claims will of course be interpreted in the context set out by the method description, but it is entirely normal for a patent to describe the state of the art before discussing a novel method (about which actual claims are then made). (IANAL)