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Indefiniteness: Are You Reasonably Certain?

The indefiniteness standard has, until recently, been very high—only an “insolubly ambiguous claim” was considered indefinite (see, e.g., Honeywell Intern., Inc. v. International Trade, 341 F. 3d 1332, 1338–9 (Fed. Cir. 2003))—but recent events have made it easier to invalidate a claim as being indefinite.  In Nautilus, Inc. v. Biosig Instruments, Inc., the Supreme Court instituted potentially drastic changes to the jurisprudence of indefiniteness by eliminating the “insolubly ambiguous standard” and instead requiring that claims must inform a person of skill in the art as to their scope “with reasonable certainty.”  134 S. Ct. 2120, 2129 (2014).  Questions immediately arose as to how courts were going to apply this new test, as the Supreme Court provided no substantive discussion when laying it out.  The Federal Circuit has given  insight into its interpretation of this new standard with its first post-Nautilus indefiniteness decision, Interval Licensing LLC v. AOL.  2014 U.S. App. LEXIS 17459 (Fed. Cir. Sept. 10, 2014).  An examination of these two cases reveals important lessons for the wary patent prosecutor.

Nautilus Changes The Test For Indefiniteness

The limitation at issue in Nautilus referred to a “spaced relationship.”  Nautilus, 134 S. Ct. at 2126.  Claim 1 of the patent at issue claimed, “A heart rate monitor … comprising … a first live electrode and a first common electrode mounted on said first half in spaced relationship with each other; ….”  The patentee argued that a "spaced relationship" meant the space between the common electrode and live electrode.  Id. at 2127.  The defendant argued that "spaced relationship" must be a distance “greater than the width of each electrode.”  Id.

The district court construed the claim and then found that the claim was indefinite under pre-AIA § 112, ¶ 2, because the available evidence “did not tell [the court] or anyone what precisely the space should be [or supply] any parameters” for determining the appropriate spacing.  Id.  The Federal Circuit reversed, finding that the claim in question was amenable to construction and not insolubly ambiguous because the intrinsic evidence provided “certain inherent parameters” that to “a skilled artisan may be sufficient to understand the metes and bounds of ‘spaced relationship.’”  Biosig Instruments, Inc. v. Nautilus, Inc., 715 F.3d 891, 899 (Fed. Cir. 2013).

The Supreme Court then reversed and remanded, finding that the Federal Circuit’s “amenable to construction” and “insolubly ambiguous” tests were too “amorphous” and did not meet the statute’s definiteness requirement.  134 S. Ct. at 2124.  The Court stated that the proper test for indefiniteness is as follows: "[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."  Id.  However, the Supreme Court did not discuss how one should apply this new test.  Several district courts have since applied the new standard, but only recently has the Federal Circuit issued a decision that gives some guidance into how it will apply this new test.

The Federal Circuit Applies Nautilus

The Federal Circuit addressed the new test for indefiniteness in Interval Licensing LLC v. AOL.  2014 U.S. App. LEXIS 17459 (Fed. Cir. Sept. 10, 2014).  Interval Licensing owns two patents, U.S. Patent No. 6,034,652 and 6,788,314, directed to generating images from content data and displaying in an unobtrusive manner the images on a device, such as a display.

Claim 1 of the ’314 patent is a representative claim:

A method for engaging the peripheral attention of a person in the vicinity of a display device, comprising the steps of: providing one or more sets of content data to a content display system associated with the display device and located entirely in the same physical location as the display device;

providing to the content display system a set of instructions for enabling the content display system to selectively display, in an unobtrusive manner that does not distract a user of the display device or an apparatus associated with the display device from a primary interaction with the display device or apparatus, an image or images generated from a set of content data;

 ’314 patent, 29:53–67 (emphasis added).

On appeal, the Federal Circuit found the claimed phrase "in an unobtrusive manner that does not distract a user" indefinite under pre-AIA 35 U.S.C. § 112, ¶2.  The Federal Circuit applied the Supreme Court's Nautilus test, stating that "[a] claim … is invalid for indefiniteness if its language, when read in light of the specification and prosecution history ‘fail[s] to inform with reasonable certainty those skilled in the art about the scope of the invention.’”  2014 U.S. App. LEXIS 17459 at *12, citing Nautilus, 134 S. Ct. at 2124.  The court focused on the fact that what was unobtrusive or distracting “depends on the preferences of the particular user” and that the patent “contemplate[d] a variety of stimuli that could impact different users in different ways.”  Id. at *15 (internal citations omitted).  Interval argued that there was a sufficient discussion as to the scope of unobtrusiveness in the specification, including a “narrow example” that illustrated the bounds of the claim.  Id. at *16, 22.  The Federal Circuit held that the claims were nevertheless indefinite because the discussion of “unobtrusive manner” in the specification was “muddled” and that the one specific example found therein was preceded by an “e.g.,” which left unclear exactly what was within the bounds of the relevant claims.  Id. at *16–23.

Lessons from Interval

The analysis provided by the Federal Circuit in Interval provides some important guidance for the prudent claim drafter.  These lessons include the following:

  • Claim language that includes a "term of degree," such as "unobtrusive manner," is not inherently indefinite.  See id. at *14 (“[W]e do not hold today, that terms of degree are inherently indefinite”).  However, subjective language of degree in a claim should be avoided because it “provides little guidance to one of skill in the art.”  Id. at *15.
  • Where a term of degree (such as "unobtrusive manner") is considered “purely subjective,” the court will look at the written description to provide clarity.  Id. at *16.
  • Where a term of degree must be used in a claim there needs to be a standard in the specification or prosecution history for “objective[ly] measuring the scope of the term in a “meaningfully precise” way.  Id. at *14-5.  It is not enough to provide a standard if that standard might mean different things to different people.  Id.
  • It is not enough to describe the subjective limitation in the written description if that description is "muddled" and a person of skill in the art cannot identify what it referenced by the language.  Id. at *16-20.  For example, in Interval the specification still left open the question of whether “unobtrusive” had temporal or spatial qualities.  Id. at *19.
  • Claim drafters must resist the urge to rely on the use of “e.g.” when describing a limitation where that limitation is subjective in nature, as this just compounds the opportunities for the court to find a claim indefinite.  Despite the otherwise “muddled” language of the written description at issue in Interval, the Federal Circuit suggested that had the one concrete example of unobtrusiveness in the specification been preceded by an “i.e.” instead of an “e.g.,” the outcome might have been different.  Id. at *23.

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Pedro F. Suarez is a Mintz Member who focuses on all aspects of patent law. Pedro's work includes intellectual property portfolio development and management, preparation and prosecution of patent applications, freedom to operate and infringement opinions, and patent monetization.

Tom Jackman