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The U.S. Supreme Court Sinks The Federal Circuit’s Indefiniteness Standard In Nautilus Nautilus, Inc. v. Biosig Instruments, Inc.

(U.S. Supreme Court, Decision of 2 June, 2014, No. 13-369, Nautilus, Inc. v. Biosig Instruments, Inc.)

The Supreme Court’s unanimous decision lowered the standard for finding a patent claim indefinite under 35 U.S.C. § 112 ¶ 2.

Previously, the Federal Circuit would find a claim term indefinite “only when it is ‘not amenable to construction’ or [is] ‘insolubly ambiguous.’”  BioSig Instruments, Inc. v. Nautilus, Inc., 715 F.3d 891, 899 (Fed. Cir. 2013) (quoting Datamize LLC v. Plumtree Software, Inc., 417 F.3d 1342, 1347 (Fed. Cir. 2005)).   The Supreme Court has now rejected that approach for not reflecting the level of precision required by 35 U.S.C. § 112 ¶ 2, holding instead that “a patent is invalid for indefiniteness if its claims. . . fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”

At issue was U.S. Patent No. 5,337,753 concerning a heart-rate monitor used with exercise equipment.  Prior heart monitors were viewed as inaccurate because they could not distinguish between electrical signals associated with heartbeats and electrical signals from other muscles.  The patent claimed a way to solve that problem by mounting both “common” and “live” electrodes with a “spaced relationship” on a bar held by the user.

The District Court granted summary judgment of indefiniteness on the claim term “spaced relationship,” finding that the intrinsic evidence did not inform the term’s scope.  The Federal Circuit reversed and Nautilus appealed to the Supreme Court.  On appeal, Nautilus argued that there was indefiniteness if individuals could reasonably interpret the claim’s scope differently.  Biosig argued that the claim was indefinite only if it did not provide reasonable notice of its scope.

In its decision, the Supreme Court acknowledged the competing concerns between allowing broad claim language and the precision required by § 112 ¶ 2 to provide the public clear notice of the patentee’s property right.  The “definiteness” of claim language is still to be evaluated from the perspective of one skilled in the art at the time of the filing of the patent application, in view of the patent’s specification and prosecution history.  However, § 112 ¶ 2 “mandates clarity, while recognizing that absolute precision is unattainable.”

Applying that mandate, the Court held that a patent claim is indefinite if it fails to inform, with reasonable certainty, those skilled in the art about the scope of the invention.  Without a requirement for reasonable certainty, the Court noted, “applicants face powerful incentives to inject ambiguity into their claims.”  The Court declined to apply the new “reasonable certainty” standard to determine whether “spaced relationship” rendered the claim indefinite but, instead, vacated the Federal Circuit’s judgment and remanded for further proceedings.

Under the old standard, a defendant asserting indefiniteness often could only argue that a claim term was not amenable to any construction, leaving only the plaintiff’s construction before the court.  Under the new standard, the defendant has the option to proffer a construction different from that of the plaintiff and argue that if the court finds both constructions valid, the claim language lacks “reasonable certainty” and is, therefore, indefinite.  We expect an uptick in the use of the indefiniteness defense and new guidelines from the Federal Circuit for applying the “reasonable certainty” test.