On June 2, 2014, the Supreme Court issued its opinion in Nautilus v. Biosig Instruments (available here). The Supreme Court unanimously reversed the Federal Circuit’s standard for determining whether a patent was indefinite under 35 U. S. C. §112, ¶ 2, which requires that a patent specification “conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as [the] invention.” The Federal Circuit had found that “a patent claim passes the § 112, ¶ 2 threshold so long as the claim is ‘amenable to construction,’ and the claim, as construed, is not ‘insolubly ambiguous.’” The Supreme Court reversed, and announced a new, “reasonable certainty” test:
We conclude that the Federal Circuit’s formulation, which tolerates some ambiguous claims but not others, does not satisfy the statute’s definiteness requirement. In place of the “insolubly ambiguous” standard, we hold 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. . . .
[W]e read §112, ¶2 to require 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 definiteness requirement, so understood, mandates clarity, while recognizing that absolute precision is unattainable.
The decision therefore has the effect of making it easier for defendants to challenge a patent’s validity.