Claims must define the scope of the invention with reasonable certainty

The Supreme Court vacates and remands Federal Circuit's judgment that heart-rate monitor patent claims are not indefinite under § 112.

The Supreme Court held that "a patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention." Slip op. at 1.

Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. ___ (June 2, 2014) (GINSBURG for a unanimous Court) (CAFC: Wallach) (S.D.N.Y.: Hellerstein) (5 of 5 stars)

In evaluating definiteness, the Supreme Court noted these undisputed principles: (1) "definiteness is to be evaluated from the perspective of someone skilled in the relevant art"; (2) "in assessing definiteness, claims are to be read in light of the patent's specification and prosecution history"; and (3) "[d]efiniteness is measured from the viewpoint of a person skilled in [the] art at the time the patent was filed." Id. at 8-9 (brackets in original).

The Supreme Court emphasized that the definiteness requirement represents a "delicate balance" between the limitations of language and the need to provide clear public notice of patent scope. Id. at 9. Thus, "[t]he definiteness requirement mandates clarity, while recognizing that absolute precision is unattainable." Id. at 11.

The Supreme Court further rejected the Federal Circuit's "insolubly ambiguous" and "amenable to construction" standards for indefiniteness, explaining that "[i]t cannot be sufficient that a court can ascribe some meaning to a patent's claims; the definiteness inquiry trains on the understanding of a skilled artisan at the time of the patent application, not that of a court viewing matters post hoc." Id. at 12 (emphasis in original). The Supreme Court also rejected the notion that the presumption of validity justified a more relaxed definiteness standard, because "this presumption of validity does not alter the degree of clarity that §112, ¶2 demands from patent applicants." Id. at 13, n.10. However, the Supreme Court left open the possibility that factual disputes pertinent to indefiniteness could be subject to the clear-and-convincing-evidence standard.

The Supreme Court declined to apply its indefiniteness test to the claims at issue, instead remanding the issue to the Fed Cir.