The Federal Circuit has had few opportunities to address the new standard for proving indefiniteness since the Supreme Court relaxed the standard from “insoluble ambiguity” to “reasonable certainty” more than two years ago in Nautilus v. Biosig. Recently, however, the Federal Circuit applied Nautilus in affirming decisions in parallel cases, Icon Health & Fitness, Inc. v. Polar Electro Oy and Icon Health & Fitness, Inc. v. Garmin International, Inc., finding Icon’s asserted patent invalid as indefinite.

Icon’s Patent Held Indefinite

Icon owns a “virtual personal trainer” patent on an exercise and health system capable of providing feedback and encouragement, which it asserted against Polar Electro’s and Garmin’s fitness monitoring devices. The patent claims at issue include the terms “in-band communication,” “out-of-band communication,” and a “relationship” between the in-band and out-of-band communication. While the specification of Icon’s patent makes it clear that “in-band” and “out-of-band” communication are distinct from one another, there is no explanation of the relationship between the two.

The new “reasonable certainty” test for indefiniteness articulated in Nautilus asks whether the claims, “viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty.” The District Court was unable to rely solely on intrinsic evidence to construe the terms and asked the parties to put forth expert testimony regarding the proper definitions of the terms. Relying on that expert testimony, the District Court found the terms ambiguous and incapable of construction and thus held Icon’s patent invalid.

The Indefiniteness Arguments Presented to the District Court

Icon’s expert opined that because the patent makes it clear that “in-band” and “out-of-band” communication are distinct, that alone is sufficient to render the claims definite and capable of construction. Polar’s expert agreed that the two terms are distinct, but argued that Icon’s patent does not provide any guidance to a person of ordinary skill as to what constitutes “in-band” versus “out-of-band” communication or how the two are related, rendering the claims indefinite.

Polar’s expert also cited ten extrinsic prior art patents and text books that, unlike Icon’s patent, each “define[] a reference that allows the reader to differentiate in-band from out-of-band in relation to that reference.” Relying on these ten extrinsic references, the District Court concluded that the disputed terms “only have meaning in a given context with a defined reference.” As a result, the Court held the terms indefinite.

The Federal Circuit Gives Deference and Upholds the Indefiniteness Ruling

In reviewing the District Court’s decision, the Federal Circuit relied on Teva v. Sandoz. Under Teva, while the ultimate interpretation of a claim term remains a legal question which the Federal Circuit reviews de novo, a factual finding by a district court that bears on the question - even if effectively dispositive of the issue - must be given deference and be reviewed for clear error. Despite the Federal Circuit’s historical reluctance to give deference to district courts, it determined the District Court’s reliance on the ten extrinsic references was a finding of fact, and reviewed the decision for clear error.

Icon was unable to convince the Federal Circuit of any clear error in the District Court’s finding of indefiniteness, so Polar prevailed (Garmin was essentially along for the ride, since Icon’s case against it was dismissed due to issue preclusion after Polar had won the indefiniteness issue at the District Court). Due to the deference required under Teva, the Federal Circuit had “reasonable certainty” that the District Court’s finding of indefiniteness was correct.

Because claim construction based on intrinsic evidence remains subject to de novo review, it continues to carry a significant risk of reversal on appeal. As the application of Teva by the Federal Circuit in Icon shows, however, submitting extrinsic evidence during claim construction may be an effective strategy for increasing the likelihood of having validity determined with greater certainty by a district court.