The Court of Appeals for the Federal Circuit, in Apple Inc. v. Andrea Electronics Corp., 949 F.3d 697 (Fed. Cir. Feb. 7, 2020), upheld the PTAB’s claim construction of the term “periodically” to only mean “at regular intervals of time” based on the disclosure of regular intervals in a preferred embodiment. The Court held that, while limitations of a preferred embodiment should not generally be read into the claims, when the plain language of the claim covers only a single preferred embodiment and the term at issue is only discussed with respect to the preferred embodiment in the specification, it is questionable whether the patentee may assert any broader scope.