Setting the Standard for Indefiniteness of Patent Claims

The Supreme Court recently resolved a question about definiteness with hopes that courts and the patent bar will not be left “at sea without a reliable compass.” In Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (2014), the court held that § 112 of the Patent Act 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.”

The facts of this case date to the 1990s, when Biosig allegedly disclosed its patented heart rate monitor technology to StairMaster Sports Medical Products, Inc., who then incorporated the technology into its machines without ever acquiring a license to do so. Nautilus eventually acquired the StairMaster brand, and according to Biosig, continued to sell machines with the patented heart rate monitor. In 2004, Biosig filed a patent infringement suit against Nautilus.  Based on the filing of this suit, Nautilus asked the Patent and Trademark Office (PTO) to reexamine the patent. The parties voluntarily dismissed the suit without prejudice while they waited for the PTO to issue its findings, and when the PTO issued a determination that the claim at issue was indeed patentable, Biosig reinstated the case. The district court granted Nautilus summary judgment, concluding that the patent was indefinite under § 112. The Federal Circuit reversed and remanded, finding that a claim is indefinite only when it is “not amenable to construction” or “insolubly ambiguous.”

The thrust of this case hinges upon the Supreme Court’s determination that the Federal Circuit’s holding was incompatible with the § 112 precision requirements. Since § 112 of the Patent Act requires a patent specification to “conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as [the] invention,” the court found that the Federal Court’s tests for indefiniteness could leave room for confusion.

The Supreme Court reached this conclusion by analyzing not only the points of conflict in the case, but also those points on which the parties agreed: that definiteness should be evaluated from the perspective of someone skilled in the art, claims should be read in light of the patent’s specification and prosecution history, and definiteness as measured by the person skilled in the art should be evaluated at the time the patent was filed. The parties disagreed, however, on exactly how much imprecision § 112 allows under definiteness standards.

As the court recognized, there is a struggle under § 112 to achieve an appropriate balance. The definiteness requirement must “take into account the inherent limitations of language,” yet patents must be “precise enough to afford clear notice of what is claimed, thereby ‘appris[ing] the public of what is still open to them.’” Without the correct formula to address meaningful definiteness, patent applicants “face powerful incentives to inject ambiguity into their claims.” 

Although the Supreme Court just decided this case, one thing seems clear – litigants with poorly drafted patent claims will likely have a more difficult time defending them in court in the future.