On June 2, 2014, the unanimous Supreme Court of the United States, in Nautilus, Inc. v. Biosig Instruments, Inc., a case that focused on the standard for compliance with the “definiteness” requirement of 35 U.S.C. § 112, ¶ 2, rebuffed the “insolubly ambiguous” standard of the U.S. Court of Appeals for the Federal Circuit holding that a claim fails to comply with the statue if the claim “read in the light of the specification and the prosecution history, fails to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”

Section 112, ¶ 2, requires a patent claim “particularly point[] out and distinctly claim[] the subject matter which the applicant regards as [the] invention.”  Justice Ginsberg articulated the proper standard for the compliance with the statute, explaining that the Federal Circuit’s current formulation—“not amenable to construction” or “insolubly ambiguous”—“lacked the precision § 112, ¶ 2, demands.”

Case Background

Biosig Instruments, Inc. (Biosig) holds a patent directed to an improved heart rate monitor associated with exercise machines.  The patent claimed improvements in heart rate measurements [electrocardiogram (ECG) signals] attained by eliminating interfering signals [electromyogram (EMG) signals] emitted by skeletal muscles during exercise.

The patent described a cylindrical bar with sensors intended to be gripped by both hands to measure ECG signals.  The claim in issue recites a “heart rate monitor for use by a user in association with exercise apparatus and/or exercise procedure,” comprising, on each half of the cylindrical bar, a live electrode and a common electrode “mounted in a spaced relationship with each other.”  The claim construction dispute centered on the “spaced relationship” claim language.

Procedural History

After Biosig sued Nautilus, Inc. (Nautilus) for patent infringement, Nautilus petitioned the U.S. Patent and Trademark Office (PTO) to reexamine the Biosig patent.  In the reexamination, Biosig submitted a declaration by the inventor, who explained that the patent sufficiently informed a person skilled in the art how to configure the electrodes “to produce equal EMG [signals] from the left and right hands.”  The declaration noted that some “trial and error” would be necessary to account for the different spacing, shape, size and material of the electrodes on different exercise machines.  The PTO ultimately confirmed the patent.

Back in the district court, during Markman, the court construed the term “spaced relationship” to mean that “there is a defined relationship between the live electrode and the common electrode on one side of the cylindrical bar, and the same or a different defined relationship between the live electrode and the common electrode on the other side of the bar,” without any reference to the electrodes’ width.  Based on that construction, Nautilus moved for summary judgment, arguing that the term “spaced relationship” was indefinite under § 112 ¶ 2.  The district court granted the motion, noting that the term failed to “tell anyone what precisely the space should be” or even supply “any parameters” to determine the appropriate spacing.

After Biosig appealed, the Federal Circuit reversed.  IP Update, Vol. 16, No. 5.  The majority, relying on a standard articulated in the 2005Datamize case (IP Update, Vol. 10, No. 1), stated that a claim is indefinite “only when it is ‘not amenable to construction’ or ‘insolubly ambiguous.’”  The Federal Circuit panel majority found the claim in issue was not indefinite because the claim language, specification and figures disclosed certain inherent parameters delineating the boundaries of the claim.  For example, the maximum distance between the live and common electrodes cannot be greater than the width of a user’s hands because the patent required the live and common electrodes to independently detect electrical signals at two distinct points of a hand.  Likewise, the distance cannot be so small so as to merge into a single electrode.

The panel majority also found that the claim’s functional provisions provided additional insight into the meaning of “spaced relationship,” concluding that a person of ordinary skill would know how to attain the equalization and elimination of EMG signals by adjusting electrode design variables, including spacing.

In the concurring opinion, Judge Schall agreed that the district court erred in its finding of indefiniteness, but would not have considered the functional limitation, i.e., the removal of EMG signals, in addressing the issue of indefiniteness of the “spaced relationship” claim term.

The Supreme Court granted certiorari to consider the issue of whether the Federal Circuit’s articulation of the standard for compliance with § 112, ¶ 2 was proper.  (IP Update, Vol. 17, No. 1).

Supreme Court Decision

Balancing Limits of Language Against Precision

Justice Ginsberg explained that § 112 entails a delicate balance, considering the inherent limitations of language.  The Supreme Court recognized that some modicum of uncertainty was the price of ensuring the appropriate incentives for innovation.  At the same time, a patent must be precise enough to afford clear notice to the public of what is claimed and avoid a “zone of uncertainty which enterprise and experimentation may enter only at the risk of infringement claims.”  Absent a meaningful definiteness check, the Supreme Court noted that applicants face powerful incentives to inject ambiguity into their claims.

Cognizant of the competing concerns, the Supreme Court held that § 112, ¶ 2 “require[s] that a patent’s claims, read in light of the specification and prosecution history, inform those skilled in the art [at the time the patent was filed] about the scope of the invention with reasonable certainty.”

Federal Circuit Formulations Too Imprecise

The Supreme Court faulted the Federal Circuit’s “not amenable to construction” or “insolubly ambiguous” formulation of the standard as lacking the precision demanded by §112, ¶2, which could result in lower court confusion.  Justice Ginsberg explained:

It 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.  To tolerate imprecision just short of that rendering a claim “insolubly ambiguous” would diminish the definiteness requirement’s public-notice function and foster the innovation-discouraging “zone of uncertainty,” ... against which this Court has warned.

While acknowledging that the phrase “insolubly ambiguous” may be simply a shorthand label for a more probing inquiry that the Federal Circuit applies in practice and that the Federal Circuit’s fuller explications of the term may track § 112, ¶ 2 more closely, Justice Ginsberg believed lower courts required more guidance: “ … although this Court does not ‘micromanage the Federal Circuit’s particular word choice’ in applying patent-law doctrines, we must ensure that the Federal Circuit’s test is at least probative of the essential inquiry.”  Justice Ginsberg explained that the Federal Circuit’s “insolubly ambiguous” language “can leave courts and the patent bar at sea without a reliable compass.”

Vacate and Remand

The Supreme Court declined to decide whether the patent was indefinite under the proper standard (“we are a court of review, not of first view”) and vacated and remanded the case for reconsideration of the indefiniteness issue under the proper standard.

Practice Note

The Supreme Court’s reaffirmation of the public notice function served by the claim definiteness inquiry and its clarification of the appropriate standard will likely result in more challenges to patent claims under § 112, ¶ 2, as well as an increased focus and reliance on expert opinions as to the meaning and scope of challenged claims to one of ordinary skill in the art.