It has been a little more than a year since the Supreme Court rendered its decision in Nautilus, lowering the standard for finding patent claim terms indefinite. Many commentators at that time predicted the decision would have broad implications for all patent cases where definiteness is at issue. Two recent cases from the District of Delaware demonstrate the accuracy of those predictions as judges in Delaware have seized upon the holding in Nautilus to find patent claim terms indefinite. Practitioners asserting or defending against patent claims would do well to acquaint themselves with the strategies and pitfalls raised by the recent decisions to ensure they provide the best advocacy.

The definiteness requirement for patent claim terms is rooted in 35 U.S.C. § 112, ¶ 2, which provides that “the specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.” The old Federal Circuit standard prior to Nautilus upheld claims as definite so long as they were “amendable to construction” and not “insolubly ambiguous.” The Supreme Court altered that standard in Nautilus and now requires “that a patent’s claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty.” Nautilus, Inc. v. Biosig Instruments, Inc., 134 S.Ct. 2120, 2129 (2014). The Federal Circuit has scoffed at the modified standard provided by the Supreme Court, noting that lower courts “may now steer by the bright star of ‘reasonable certainty,’ rather than the unreliable compass of ‘insoluble ambiguity.’” Biosig Instruments, Inc. v. Nautilus, Inc., 783 F.3d 1374, 1379 (Fed. Cir. 2015).

Nonetheless, the holding in Nautilus was recently cited by Judge Sue Robinson in the District of Delaware in finding the claims of 6 patents invalid. Cox Communs. Inc. v. Sprint Communs. Co., No. 12-487-SLR, 2015 U.S. Dist. LEXIS 64252 (D. Del. May 15, 2015). In Cox, the parties disputed whether the claim limitation “processing system” is indefinite. Cox argued that the limitation is indefinite because the structural limitation, “processing system,” is only described functionally in the patents. Sprint’s expert opined that the patents reference other patents which use the phrase “processing system,” demonstrating that a person of ordinary skill in the art would have known with reasonable certainty what is meant by the limitation. Another expert, however, countered that assertion by selecting five patents of the twenty five identified by Sprint’s expert as using “processing system” in their claims, and explaining that the phrase is used differently in each of the five patents sampled, with different structures and specialized software to perform widely differing functions.

The court in Cox concluded that the physical structures were only functionally described by the claims and by the patent specifications and, thus, did not pass muster under Nautilus as a person of ordinary skill in the art is not provided with the bounds of the claimed invention. The court agreed that the limitation “processing system” is used differently in a sampling of other patents, and found it significant that the parties did not provide, nor was the court able to find, a dictionary definition for the phrase “processing system.” The court rejected Sprint’s proposed construction because it felt that it only described the “processing system” by its function rather than structure, and the court concluded that there is no established meaning in the art for the disputed limitation.

Another recent decision in the District of Delaware by Judge Gregory Sleet applied the holding in Nautilus to find a patent claim term indefinite. Bayer Intellectual Prop. GmbH v. Warner Chilcott Co., No. 12-1032-GMS, 2015 U.S. Dist. LEXIS 52061 (D. Del. Apr. 21, 2015). In Bayer, the court previously issued a claim construction order finding that words of degree in a claim term including “high,” “low,” “satisfactory,” and “reliable” had no standards against which to draw comparisons, and that the patent offered no suggestions for how to measure those criteria. Bayer had not sought reconsideration of the claim construction ruling, but nonetheless contended in opposing a summary judgment motion that the disputed term is not indefinite because one skilled in the art would understand with reasonable certainty its meaning, as demonstrated by extrinsic evidence. Bayer provided dozens of pieces of extrinsic evidence, as well as a supplemental declaration from its expert, in support of a new argument that the disputed term and the words of degree simply indicate that the claimed invention performs comparably to other products on the market.

The court found that Bayer’s efforts to reargue claim construction with entirely new evidence was improper and, thus, maintained the finding of indefiniteness. The decision went on to indicate that the court would reach the same result of indefiniteness for several reasons even if it were to accept the additional extrinsic evidence and allow Bayer to assert a new construction. First, the court explained that the proposed construction and the underlying extrinsic evidence conflicts with the intrinsic record of the patent, which violates a basic tenet of claim construction. Second, the court reasoned that conflicting interpretations of the disputed term offered by Bayer’s expert in his two declarations underscored the fact that the patent fails to inform, with reasonable certainty, those skilled in the art about the scope of the invention. Third, the court found that Bayer’s proposed construction using the word “comparable” was itself subjective and without defined boundaries. The court thus found on summary judgment that the patent claim is indefinite and invalid.

In light of the above recent cases, it is now more important than ever for practitioners to marshal all available evidence regarding the meaning of disputed claim terms well in advance of the claim construction hearing. The gathering of evidence should include extrinsic evidence and any available dictionary definitions to show a commonly understood meaning by the plaintiff, or a showing of the lack of such evidence to demonstrate a lack of a commonly understood meaning by the defendant. The cases also show a need to have expert reports with well thought out positions ready for the claim construction hearing to compare the extrinsic evidence with the intrinsic record and support the claim construction arguments. The cases further highlight the need for proposed claim constructions to be structural for structural claim terms and to also be definite. Finally, the cases provide a reason for defendants to take a shot at indefiniteness for patent claim terms with the expectation that their arguments will be seriously considered in light of the Nautilus standard.