In Kaken, the Federal Circuit used unequivocal statements in the specification and prosecution history, upon which the Examiner relied in allowing the claims, to reverse the Board’s claim construction. Specifically, the Federal Circuit found that both the specification and prosecution history of the patent at issue in Kaken necessitated the conclusion that Kaken’s claimed method was directed to treating specifically onychomycosis, as it occurs underneath a nail bed, as opposed to a more generic class of fungal infections of the skin.
In Personalized Media, the claim language at issue included “encrypted digital information” which the Board construed as allowing for the presence scrambled analog information. After finding that neither the claim language itself nor evidence from the specification was dispositive, the Federal Circuit turned to the prosecution history of the patent at issue and held that three statements made therein provided sufficient bases to reverse the Board’s claim construction, limit the claims to digital signals and thereby avoid the prior art.
Which just goes to show, even if you take great pains to argue what the prior art is not, rather than the specific metes and bounds of the claim being prosecuted, prosecution history may still apply.