On September 15, 2020, the U.S. Court of Appeals for the Federal Circuit, in IQASR v. Wendt, found that a district court did not err in its scrutiny of the extrinsic and intrinsic evidence presented to find U.S. Patent No. 9,132,432 invalid for indefiniteness. The Federal Circuit did not perceive any clear error in the court's finding that the disputed term "magnetic fuzz" lacked a readily understood definition in its relevant field, as understood by a person of ordinary skill in the art as of the effective date of the patent application. The circuit court also reinforced a landmark U.S. Supreme Court ruling that "indefiniteness involves consideration of primarily the intrinsic evidence, viz., the claim language, the specification, and the prosecution history" which allow a person skilled in the art to recognize the scope of the claim term with reasonable certainty.

Reasonable Certainty Standard for Definiteness

In 2014, the Supreme Court, in its landmark ruling in Nautilus v. Biosig Instruments, held unanimously that "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." Because patents possess a public service function, a patent's claims must be definite enough to apprise the public at large as to what has or has not been patented. Specifically, the claims must particularly point out and distinctly claim the invention to satisfy this requirement of 35 U.S.C. § 112. Accordingly, the Court declared that the definiteness inquiry is focused upon the understanding of the skilled artisan at the time the patent application is filed and not on the patent's ability to ascribe at least some meaning to the claim term.

IQASR v. Wendt

In 2016, IQASR sued Wendt Corporation for infringing U.S. Patent No. 9,132,432, which describes a method of sorting recyclable materials from nonrecyclable materials produced during the shredding of scrapped or junked automobiles. The method recited in the '432 patent allows for an enhanced separation of nonrecyclable materials like "trash and magnetic fuzz" from recyclable materials like "plastics and metals." After a Markman hearing, the district court found the disputed term "magnetic fuzz" indefinite and invalidated the '432 patent for indefiniteness.

IQASR appealed the district court's decision, arguing that the court committed multiple legal errors in applying the law of indefiniteness and in its findings on both the extrinsic and intrinsic evidence presented. The Federal Circuit rejected IQASR's arguments and affirmed the lower court holding. Specifically, the appellate court did not find any clear error in the district court's analysis or in its determination that the disputed term "'magnetic fuzz' lacks 'a readily-understood definition in [its] field.'"

Furthermore, the Federal Circuit supported the notion that, as the trier of fact, a lower court is "entitled to weigh the expert's testimony as it thought appropriate based on the expert's qualifications and experience." The court reasoned that an expert's opinion can be used to provide context for a disputed term as extrinsic evidence, but it alone cannot be used to rebut a party's evidence that a person of ordinary skill in the art lacks understanding of the claim scope with reasonable certainty. The Federal Circuit went on to state that "[e]ven if a claim term's definition can be reduced to words, the claim is still indefinite if a person of ordinary skill in the art cannot translate the definition into meaningfully precise claim scope." IQASR's inclusion of multiple layers of definition forced a skilled artisan to "wade through a morass of uncertainty and contradiction" and included a "word salad of inconsistent indirect definitions and examples that [] flummoxed the district court." IQASR failed to provide sufficient intrinsic evidence in its patent to support a reasonable certainty that those skilled in the art would be informed about the scope of the invention, and their reliance on the subjective opinion of an expert that can change daily, depending on the expert's qualifications and experience, was insufficient to cure the defects for their patent's failure to inform a person of ordinary skill in the art about the scope of their invention, as 35 U.S.C. § 112 requires.


Ultimately, as noted above, the '432 patent's complex definitions prevented a person of ordinary skill in the art from understanding the claimed scope with reasonable certainty. The equivocation and subjectivity offered in the IQASR expert's opinion failed to cure the intrinsic ambiguities of the disputed term, "magnetic fuzz," and led to the district court discounting the importance of the more extensive use of the term "fuzz" prior to the invention date. Although the expert opinion offered context for the term, the context could not provide the precision required to define the boundaries of "magnetic fuzz." Accordingly, "a claim term does not become reasonably certain simply because a skilled artisan, when pressed, managed to articulate a definition for it."

Although the court's opinion in this case is nonprecedential, this decision further illustrates the test that the Supreme Court articulated in Nautilus for indefiniteness. The use of extrinsic evidence, such as an expert opinion, is, by itself, insufficient to resolve intrinsic ambiguities in a patent. As the Federal Circuit stated in Teva Pharmaceuticals USA v. Sandoz, "[a] party cannot transform into a factual matter the internal coherence and context assessment of the patent simply by having an expert offer an opinion on it." The determination of whether a disputed term is defined with reasonable certainty is a question of law. Expert opinions can be used to establish some context for the meaning of the term, but the expert opinion cannot be used to rebut evidence that the disputed term lacks ordinary meaning at the time the patent was filed. Accordingly, ambiguity within a patent cannot be cured just by a years-later opinion of someone with a technical degree or industry experience.

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