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Without “Reasonable Certainty,” a Patent Claim Is Indefinite

Posted by Thomas P. Howard | May 19, 2021 | 0 Comments

By James Juo.

Patent invalidity based on indefiniteness can be asserted as an affirmative defense in a patent lawsuit. To satisfy the definiteness requirement of 35 U.S.C. § 112(b), the claims of a patent must particularly point out and distinctly claim the subject matter of the invention. 35 U.S.C. § 112(b) (a patent's “specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention”). Prior to the American Invents Act (“AIA”), this definiteness requirement was referred to as Section 112, second paragraph. Indefinite claims do not adequately set forth the metes and bounds of a patent claim, and thus are invalid.  But if ambiguous claims are granted by the USPTO, then they are entitled to the presumption of validity.

Before the U.S. Supreme Court's decision in Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 134 S. Ct. 2120 (2014), courts had applied an “insolubly ambiguous” standard where a claim was indefinite only if no narrowing construction could properly be adopted. Exxon Research & Eng'g Co. v. United States, 265 F.3d 1371, 1375 (Fed. Cir. 2001). “If the meaning of the claim is discernible, even though the task may be formidable and the conclusion may be one over which reasonable persons will disagree, we have held the claim sufficiently clear to avoid invalidity on indefiniteness grounds.” Id.; cf. Modine Mfg. Co. v. U.S. Int'l Trade Comm'n, 75 F.3d 1545, 1557 (Fed. Cir. 1996) (“when claims are amenable to more than one construction, they should when reasonably possible be interpreted to preserve their validity”).

Now, however, the claims must “inform, with reasonable certainty, those skilled in the art about the scope of the invention.” Nautilus, 134 S. Ct. at 2124 (emphasis added). “The claims, when read in light of the specification and the prosecution history, must provide objective boundaries for those of skill in the art.” Interval Licensing LLC v. AOL, Inc., 766 F.3d 1364, 1371 (Fed. Cir. 2014) (emphasis added) (citing Nautilus, 134 S. Ct. at 2130). The definiteness of a patent claim is evaluated from the perspective of a person of ordinary skill in the art. Nautilus, 134 S.Ct. at 2128.

If the intrinsic evidence of the specification and the prosecution history does not provide sufficient guidance for one to discern between multiple alternative constructions, then the patent claim may be found indefinite. Dow Chem. Co. v. Nova Chem. Corp., 803 F.3d 620, 630–31 (Fed. Cir. 2015) (finding the claim language “slope of strain hardening coefficient” was indefinite in view of multiple methods of measuring the “slope”); Teva Pharmaceuticals USA Inc. v. Sandoz Inc., 789 F.3d 1334 (Fed. Cir. 2015) (finding “molecular weight” to be an indefinite claim term because measuring “molecular weight” according to “peak average,” “number average” or “weight average” could yield different results); Media Rights Techs., Inc. v. Capital One Fin. Corp., 800 F.3d 1366, 1371 (Fed. Cir. 2015) (“a claim is indefinite if its language might mean several different things and no informed and confident choice is available among the contending definitions” (internal quotations marks omitted)).

Furthermore, “a term of degree fails to provide sufficient notice of its scope if it depends ‘on the unpredictable vagaries of any one person's opinion.'” Interval Licensing, 766 F.3d at 1371 (quoting Datamize, LLC v. Plumtree Software, Inc., 417 F.3d 1342, 1351 (Fed. Cir. 2005)); see also Medicines Co. v. Mylan, Inc., 853 F.3d 1296, 1303 (Fed. Cir. 2017) (holding that forward-looking assessments would not provide reasonable certainty for a patent claim). Without “reasonable certainty,” a patent claim is invalid for indefiniteness.  Nautilus, 134 S. Ct. at 2124.

In addition, whether a claim is indefinite may be considered as part of the claim construction process in patent infringement lawsuits. Medicines Co., 853 F.3d at 1303; see also Sonix Tech. Co., Ltd. v. Publ'ns Int'l, Ltd., 844 F.3d 1370, 1378 (Fed. Cir. 2017) (“indefiniteness analysis involves general claim construction principles”). If raised during claim construction, however, the court may decide to defer a decision on indefiniteness. See United Cannabis Corp. v. Pure Hemp Collective Inc., No. 18-cv-1922-WJM-NYW, 2020 WL 376508 (D. Colo. Jan. 23, 2020) (foreseeing that the patent claim “may be indefinite” and stating the parties would be expected to address the matter of indefiniteness through summary judgment).

For the examination of patent applications before the U.S. Patent and Trademark Office (“USPTO”), however, the Packard standard is applied, providing a “claim is indefinite when it contains words or phrases whose meaning is unclear.” In re Packard, 751 F.3d 1307 (Fed. Cir. 2014) (per curiam). Patent examiners interpret patent claims under their broadest reasonable interpretation, which is a different standard from the claim construction standard, known as the Phillips standard, that district courts apply in patent infringement litigation.

Recently, a memorandum issued by the USPTO on January 6, 2021, stated that, for AIA post-grant proceedings before the Patent Trial and Appeal Board (“PTAB”), the Nautilus “reasonable certainty” standard for indefiniteness will be applied. Since 2018, in AIA post-grant proceedings, the PTAB has applied the Phillips standard for claim construction—the same standard applied by district courts in patent infringement litigation—rather than the “broadest reasonable interpretation” standard otherwise applied by the USPTO during patent prosecution. See 83 FR 51340 (Oct. 11, 2018). Having aligned the PTAB approach to claim construction in AIA post-grant proceedings with the Phillips approach used by the district courts, the PTAB now also will adhere to the Nautilus approach used by the district courts for evaluating claim indefiniteness. The memorandum asserts that this greater alignment will lead to more uniformity and predictability, improve the integrity of the patent system, and help increase judicial efficiency. Whether the Federal Circuit will agree is another matter.

The patent attorneys at Thomas P. Howard, LLC are experienced in evaluating indefiniteness and other patent issues in connection with prosecution and litigation.

About the Author

Thomas P. Howard

Thomas Howard is an experienced trial lawyer that handles intellectual property litigation nationwide, including copyright, trademark, trade secret and patent litigation, as well as complex civil litigation, including breach of contract, interference with contract, breach of fiduciary duty, conspiracy, fraud and fraudulent transfer of assets.


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