Edwards Lifesciences v. Cook, Inc. (Fed. Cir. 2009)
The four Edwards patents all relate to internal blood-vessel grafts for treating aneurisms. The grafts are designed to be inserted endovascularly without the need for open surgery. After construing the claims, N.D. Cal. District Court Judge Jeffrey White granted summary judgment of non-infringement to the two defendants, Cook and Gore. On appeal, the Federal Circuit affirmed.
Lumpy Claim Construction: Patent claim construction serves as a prime example of how litigators can take a simple issue and make it quite complicated. For their part, judges are keen to limit the issues. A common approach in claim construction is to group similar claim terms together and give them identical meaning. In this case, the patent used the terms "graft," "graft body," graft structure", "bifurcated base structure," and "bifurcated base graft structure." Examining these terms, the appellate panel agreed that these terms could properly be analyzed together because the applicant had used them "interchangeably in the specification," at least with respect to the disputed differences.
This risk of synonymous meaning is not necessarily bad. Using various terms to describe the same idea helps to flesh out the detail and scope of the idea. However, in most cases, applicants would probably be better off emphasizing distinctions between similar terms. The distinctions may well be useful for ensuring varied claim coverage.
The point from this case is that the distinctions between similar terms must be explicitly emphasized if the applicant wants to have confidence that it can later rely on the differences.
Broadening Claims:During prosecution, Edwards seemingly broadened some of its claims by amending the "intraluminar graft" elements to simply "graft" elements. Despite that change, the court found that the specification's written description still required that all grafts be intraluminal.