Edwards Lifesciences v. Cook

In this case, the patents “relate to intraluminal grafts for treating aneurisms and occlusive diseases of the blood vessels without open surgery.” (p. 2.) The main arguments involved claim construction. The patentee argued that the use of the terms “graft” and “intraluminal graft” suggested that the term “graft” was broader. The court, relying on the written description, disagreed. First, the specification used the terms interchangeably. “The interchangeable use of the two terms is akin to a definition equating these two.” (p. 11.) Second,” the only devices described in the specification are intraluminal, supporting an interpretation that is consistent with that description.” (p. 11.) Third, “the specification frequently describes an ‘intraluminal graft’ as ‘the present invention’ or ‘this invention,’ indicating an intent to limit the invention to intraluminal devices.” (p. 12.) Fourth, the context of the claims supported this construction. The court also rejected arguments based on claim differentiation: “Even if the claim construction had rendered the dependent claim redundant, the doctrine of claim differentiation does not require us to give the ‘graft’ devices their broadest possible meaning. We may instead limit ‘grafts’ to ‘intraluminal’ devices, as demanded by the specification.” (p. 13; see also id. (“Different terms or phrases in separate claims may be construed to cover the same subject matter where the written description and prosecution history indicate that such a reading of the terms or phrases is proper.”) (quoting Nystrom v. TREX Co., 424 F.3d 1136, 1143 (Fed. Cir. 2005).)

Regarding another term, the patentee made another claim differentiation argument, this one based on the fact that a dependent claim added a requirement for a wire that was not expressly found in the independent claim. This is normally the strongest case for claim differentiation but it was dismissed quickly: “[C]laim differentiation is a rule of thumb that does not trump the clear import of the specification. Here, the specification and the parties’ agreement in the district court make clear that the claimed graft devices require wires.” (p. 16 (citation omitted).)

Concerning another term, the court stated that, for a definition provided by the patentee, “the location within the specification in which the definition appears is irrelevant.” (p. 20-21.) Accordinlgy, “the specification’s use of ‘i.e.’ signals an intent to define the word to which it refers … and that definition was not limited to the embodiment being discussed.” (p. 21.)