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Indefinite Patent Claim Language – A Fatal Flaw

The Patent Appeals Court (the Federal Circuit) reversed its previous decision that the subject patent claims were not indefinite, because there was an intervening change of law when the Supreme Court altered the standard for indefiniteness to require that the “claims, read in light of the specification delineating the patent, and the prosecution history, [must] to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”  See Dow Chemical Co. v. Nova Chemicals Corp., 803 F.3d 620 (Fed. Cir. 2015)(Available Here) and see  Nautilus, Inc. v. Biosig Instruments, Inc., 134 S. Ct. 2120 (2014).  

In Dow Chemical, the only issue before the Federal Circuit was whether, under Nautilus, the supplemental damages award must be reversed.  In the prior case, the Federal Circuit had affirmed the jury finding that the claims were infringed and not invalid, and that the asserted claims were not indefinite.  The district court subsequently conducted a bench trial for the supplemental damage period and the parties appealed.  In reviewing the supplemental damage award, the Federal Circuit held that, under the new Nautilus standard for indefiniteness, the claims are indefinite and reversed the award of supplemental damages.

Three conditions must be satisfied to reopen a previous decision under the change of law exception for both law of the case and issue preclusion. First, the governing law must have been altered.  Second, the decision sought to be reopened must have applied the old law.  Third, the change in law must compel a different result under the facts of the particular case.  The Federal Circuit found all the conditions met allowing them to decide the case under the new Nautilus standard.

The relevant claim language at issue in the Dow case required “a slope strain hardening coefficient greater than or equal to 1.3.”   Nova argued that the patents are indefinite for failing to teach a person having ordinary skill in the art how to measure the “slope of strain hardening.”  The Federal Circuit analyzed the claim under the Supreme Court’s new standard, “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.  

The Federal Circuit found that, under Nautilus, the claims, when read in light of the specification and the prosecution history, must provide objective boundaries for those of skill in the art.  See  Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364, 1371 (Fed. Cir. 2014).  Although the Court recognized that some modicum of uncertainty may be tolerated, the patent and the prosecution history must disclose a single known approach or establish that, where multiple known approaches exist, a person having ordinary skill in the art would know which approach to select.  See Teva Pharm. USA, Inc. v. Sandoz, Inc., 789 F.3d 1335, 1341 (Fed. Cir. 2015).

Utilizing the Nautilus standard, the Federal Circuit found that the claims were indefinite, because there were four methods to determine the maximum slope, and there was no question that each of the methods may produce different results.  The four methods produced different slope strain hardening coefficients.  Because the methods do not always produce the same results, the method chosen for calculating the slope of strain hardening could affect whether or not a given product infringes the claims.  Neither the claims nor the specification discussed the four methods or provided any guidance as to which method should be used or even whether the possible universe of methods is limited to these four methods.  Therefore, the required guidance was not provided by the claims, specification, and prosecution history and the claims are invalid as indefinite.

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