Supreme Court Announces Appropriate Standard for Determining Patent Indefiniteness under 35 U.S.C. § 112

In Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (2014), the United States Supreme Court rejected the long-standing Federal Circuit test for definiteness under 35 U.S.C. § 112. The Supreme Court's ruling replaces the "insolubly ambiguous" standard with a new "reasonable certainty" standard. This decision will likely have a significant impact on both patent prosecution and litigation practice in the United States.

Section 112 of the Patent Statute requires that a patent specification "shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter" regarded as the invention. Non-compliance with this statutory definiteness requirement renders "the patent or any claim in suit" invalid. 35 U.S.C. § 282.

Under the now-defunct standard Federal Circuit standard, a patent claim was indefinite if it was "not amenable to construction" or, if construed, it remained "insolubly ambiguous." See, e.g., Biosig Instruments, Inc. v. Nautilus, Inc., 715 F.3d 891, 897-98 (Fed. Cir. 2013). Criticizing this old standard, the Supreme Court noted that it "can breed lower court confusion" due to its lack of precision and concluded that because it "tolerates some ambiguous claims but not others, [it] does not satisfy the statute's definiteness requirement." The Supreme Court found the resulting imprecision to conflict with the public-notice function of the definiteness requirement. 

Under the new standard articulated by the Supreme Court, "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." Nautilus, 134 S. Ct. at 2124. In conjunction, the Supreme Court reaffirmed several contours of the Section 112 definiteness inquiry: 

(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) "definiteness is measured from the viewpoint of a person skilled in the art at the time the patent was filed."

Id. at 2128. The Supreme Court remanded the case to the Federal Circuit to apply the newly-articulated standard for indefiniteness.

The impact of the Nautilus opinion may well be far-reaching, although its immediate effects are likely to be unknown for some time as a result of the remand to the Federal Circuit . In the context of patent prosecution, the Supreme Court has recognized the pivotal role a patent drafter plays in ensuring that patent claims are written in a way to convey reasonable certainty as to the scope of the invention. According to the Supreme Court, the "temptation" to draft patent claims vaguely and to "defer clarity at all costs" must be eliminated. The United States Patent and Trademark Office will assuredly apply the new standard for indefiniteness and require inventors and applicants to draft or amend claims with sufficient clarity to avoid a Section 112 rejection.

In litigation, the impact may even be more profound. Notably, the Supreme Court tempered its formulation of the appropriate definiteness inquiry with the realization of the necessity of striking a "delicate balance" between competing definiteness concerns. On the one hand, "the definiteness requirement must take into account the inherent limitations of language," with "[s]ome modicum of uncertainty" being the "price of ensuring the appropriate incentives for innovation." On the other hand, "a patent must be precise enough to afford clear notice of what is claimed, thereby 'apprising the public of what is still open to them.'" Proving the extent to which this balance has been—or not been—sufficiently struck will likely be subject to debate between patent holders and accused infringers.