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Written Description and Prosecution History May Trump the Plain Language of the Claims and the Doctrine of Claim Differentiation During Claim Construction

September 22, 2009

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Last Month at the Federal Circuit - October 2009

Judges: Lourie (author), Rader, Moore

[Appealed from: N.D. Cal., Judge White]

In Edwards Lifesciences LLC v. Cook Inc., No. 09-1006 (Fed. Cir. Sept. 22, 2009), the Federal Circuit affirmed the district court’s grant of SJ of noninfringement in favor of the defendants Cook Incorporated and W.L. Gore and Associates, Inc. (collectively “Cook”). The Federal Circuit determined that the district court had correctly construed certain claim terms and correctly determined that Cook’s devices did not infringe under the district court’s claim constructions.

Plaintiffs Edwards Lifesciences LLC and Endogad Research PTY Limited (collectively “Edwards”) own four patents, which are related and share a common specification. The patents relate to intraluminal grafts for treating diseases of the blood vessels. Each of the asserted claims recite two of the following structures: a “graft,” a “graft body,” or a “graft structure,” a “bifurcated base structure,” and a “bifurcated base graft structure.” Further, in each of the claims, the two elements were “anchored,” “attached,” “attachable,” or “dockable” to each other while inside a vessel. The court construed those terms (1) to be intraluminal, (2) to require wires, (3) to require that those wires be malleable, and (4) to preclude resilience from such wires. The district court determined that the Cook devices did not infringe because the devices did not contain malleable wires, as the claims required.

On appeal, the Federal Circuit agreed with the district court that, in light of the specification, the claimed “graft” devices must all be intraluminal. The Court noted that, although the construction of a claim term is usually controlled by its ordinary meaning, an alternative meaning is appropriate if the patentee distinguished that term from prior art on the basis of a particular embodiment, expressly disclaimed subject matter, described a particular embodiment as important to the invention, or acted as its own lexicographer in defining a claim term. The Federal Circuit recognized that the terms “graft” and “intraluminal graft” were consistently used interchangeably. Further, the only devices described in the specification were intraluminal, supporting an interpretation that is consistent with that description. Moreover, the Court stated, “[W]hen the preferred embodiment is described in the specification as the invention itself, the claims are not necessarily entitled to a scope broader than that embodiment.” Slip op. at 12 (quoting Chimie v. PPG Indus. Inc., 402 F.3d 1371, 1379 (Fed. Cir. 2005)). Here, the specification frequently described an “intraluminal graft” as “the present invention” or “this invention,” indicating an intent to limit the invention to intraluminal devices. Id.

The Federal Circuit also found that the claim language itself supported the district court’s construction. The Court recognized that certain claims required that the grafts be attachable “while inside of a vessel,” but noted that traditional vascular grafts are not implanted “inside of a vessel,” and “intraluminal” specifically means “inside of a vessel.” Therefore, the Federal Circuit found that the claims supported the district court’s interpretation that a “graft body” must be intraluminal rather than being part of a traditional vascular graft.

Finally, the Court agreed that claim differentiation did not require that “graft” be read differently from “intraluminal graft.” Although certain claims recited a “second graft . . . adapted to be intravascularly inserted into a lumen of [a] first graft,” the intravascular insertion and the “intraluminal grafts” were not redundant. A device could theoretically be “intravascularly inserted” but ultimately reside outside of the vessel, such as inside the heart. Further, the Federal Circuit found that the doctrine of claim differentiation did not require the district court to give the “graft” devices their broadest possible meaning if the specification did not demand it. Although Edwards pointed to certain amendments made during prosecution to urge a broader claim construction, the Court found the accompanying remarks and inventors’ statements indicated that the devices must be intraluminal.

The Federal Circuit then agreed that the claims required the devices to include wires because the devices were intraluminal and because each of the claims recited an attachment that required wires. In reaching this conclusion, the Court noted that the parties had agreed at trial that intraluminal devices required wires. Moreover, every embodiment described in the specification and shown in the drawings included wires. In addition, every claim also required that the two graft components be “anchored,” “attached,” “attachable,” or “dockable” to each other, and the parties agreed that only wires performed that function. In addition, the Federal Circuit disagreed with Edwards’s argument that because certain dependent claims recited “a wire structure,” the doctrine of claim differentiation required the Court to find that the independent claims did not require wires. The Court stated that “claim differentiation is a rule of thumb that does not trump the clear import of the specification,” and the specification and the parties’ agreement in the district court made it clear that the claimed graft devices required wires. Id. at 16.

Third, the Federal Circuit found that the wires required by the claims must be malleable because the inventors disclaimed the use of resilient, or self-expanding, wires. The Court noted that the inventors had disparaged prior art resilient wires in their “background art” section of the specification. Therefore, when the claims were read in light of the specification, a person of ordinary skill in the art would understand that the invention required malleable, rather than resilient, wires.

Further, although the inventors canceled claims during prosecution that required “malleable wires” and replaced them with claims requiring only “wires,” the inventors conducted the prosecution as if the wires were required to be malleable. For example, in attempting to distinguish over certain prior art, Edwards stated that the written description expressly taught wires that were malleable and not self-expanding. Thus, the change in claim language did not affect the breadth of the claims because the inventors’ statements indicated that the claims remained narrow.

Fourth, the Federal Circuit agreed that, in the context of the specification, malleable wires and resilient wires were mutually exclusive. The specification defined “malleable” to exclude any substantial resilience, and the Court found that that definition must override any ordinary meaning of the word “malleable” that might allow for substantial resilience.

Based on this construction, the Federal Circuit affirmed the grant of SJ of noninfringement for the accused Cook devices. The Court found that the wires in the accused devices were primarily resilient, self-expanding wires and therefore were not malleable, as required by the court’s claim construction. In addition, the Court affirmed the district court’s grant of SJ of noninfringement under the DOE because the inventors had disclaimed resilient wires and therefore could not use the DOE to recapture the disclaimed scope.

Summary authored by Matthew R. Van Eman, M.D., Esq.