This morning, in Nautilus, Inc. v. Biosig Instruments, Inc., the Supreme Court rejected the Federal Circuit’s formulation of the definiteness requirement under 35 U.S.C. § 112, para. 2.  Under the now-abandoned iteration of the definiteness test, claims were deemed to have satisfied the statutory requirement so long as they were “amenable to construction” and “not insolubly ambiguous.”  In place of this standard, the Supreme Court held that a claim is indefinite if, it fails to “inform those skilled in the art about the scope of the invention with reasonable certainty,” when read in light of the specification delineating the patent, and the prosecution history.  (Slip op. at 1, 11.)  In adopting this standard, the Court rejected the patentee’s (and government’s) suggestion that claims should be found sufficiently definite when “provide reasonable notice of the scope of the claimed invention.”  (Slip. op. at 9.)  That said, the Court did not simply adopt the accused infringer’s proposed standard­­ either—which would have invalidated claims whenever “readers could reasonably interpret the claim’s scope differently.”  (Id.)

The Court acknowledged the competing concerns underlying the definiteness requirement.  Imprecision of the written word places real limits on a patentee’s ability to define his/her invention, but competitors should not be forced to enter a “zone of uncertainty” when attempting to delineate what is fair game from what has been excluded from the public domain.  (Slip. op. at 9-10.)  The Court also recognized a concern that “patent applicants face powerful incentives to inject ambiguity into their claims.”  (Slip. op. at 10.)  The Court felt that the balance of the concerns warranted placing the onus on the patent drafter to define the invention with “reasonable clarity.”

While the precise boundaries of this new standard will not be known until the Federal Circuit has had a few chances to apply the standard, the Supreme Court did provide some guidance by indicating that the Federal Circuit’s exposition of the old standard may more closely align with the new standard.  (See Slip. op. at 12 (referencing statement in underlying Federal Circuit opinion stating that “if reasonable efforts at claim construction result in a definition that does not provide sufficient particularity and clarity to inform skilled artisans of the bounds of the claim, the claim is insolubly ambiguous and invalid for indefiniteness”).)  While patent litigants will debate the weight to ascribe to decisions employing the old standard, two words that we can all drop from our vernacular are “insolubly ambiguous.”

One point of additional interest is that the Supreme Court expressly refused to address whether the “clear-and-convincing” standard should apply to the invalidity defense of indefiniteness.  The Supreme Court noted that the Federal Circuit had treated definiteness as a legal issue to be reviewed without deference—suggesting the PTO’s decision would deserve no such deference—but concluded that the applicability of the presumption of validity is a “question[] for another day.”  (Slip. op. at 13.)