See that's the thing... He gave it a name sure, but that creepy chick with all the arms mentioned it to Kurotsuchi and she's from WAY before Urahara's time, so it's totally possible that there was something along those lines there beforehand, he just gave it a name. It's like the whole Mod Soul thing, people assumed that was Urahara's invention, but now we find out it's Hikifune's....