Relative Terms Sufficient for Reasonable Certainty

Holding

In Niazi Licensing Corp. v. St. Jude Med. S.C., Inc., No. 21-1864 (Fed. Cir. Apr. 11, 2022), the Court of Appeals for the Federal Circuit (“Federal Circuit”) reversed the district court’s holding that the claim terms “resilient” and “pliable” were indefinite. The Federal Circuit remanded the case to resolve the infringement issue and any remaining invalidity defenses. While the Federal Circuit addressed several other issues, this post analyzes the portion of the opinion related to the indefiniteness issue.

Background

Niazi sued St. Jude for infringement of U.S. Pat. No. 6,638,268 (“the ’268 patent”) directed to a double catheter for cannulating the coronary sinus without significant manipulation. Representative claim 1 reads:

1. A double catheter, comprising: an outer, resilient catheter having shape memory and a hook shaped distal end configured for cannulation of the coronary sinus with at least one curved bend; an inner, pliable catheter slidably disposed in the outer catheter and of greater length than the outer catheter so that a distal end portion of the inner catheter can be extended or retracted from a distal end opening of the outer catheter to vary the overall length of the double catheter ….

Federal Circuit

Under the Supreme Court standard from Nautilus, Inc. v. Biosig Instruments, Inc., 572 U.S. 898, 901 (2014), a claim must inform one of ordinary skill in the art with “reasonable certainty” as to the scope of the claim. Id. at *9. The question is “whether the use of descriptive phrasing in the claim results in a claim that ‘fail[s] to inform, with reasonable certainty, those skilled in the art about the scope of the invention.’” Id. at *11 (quoting Nautilus, 572 U.S. at 901). To answer this question, the court must consider whether “the intrinsic record—the patent’s claims, written description, and prosecution history —along with any relevant extrinsic evidence” provides or help identifies the necessary objective boundaries for claim scope. Id. at *14.  

According to the Federal Circuit in this case, the terms “resilient” and “pliable” are broad, but not uncertain. Id. at *14.

With regards to the term “resilient,” the Federal Circuit based its decision on other claim language (“shape memory,” “sufficient stiffness,” and exemplary resilient materials recited) and the description in the specification. Id. at *14-15. The Federal Circuit concluded that in light of this guidance, “a person of ordinary skill reading the claims and written description would know of exemplary materials that can be used to make a resilient outer catheter, i.e., one that has shape memory and stiffness such that it can return to its original shape.” Id. at *15.

The Federal Circuit found less guidance in the claim language for the phrase “pliable,” but found guidance in the specification’s examples of a “pliable” inner catheter. Id.

The Court cited Sonix Tech. Co. v. Publ’ns Int’l, Ltd., 844 F.3d 1370 (Fed. Cir. 2017) and Enzo Biochem, Inc. v. Applera Corp., 599 F.3d 1325 (Fed. Cir. 2010), as support for using guidance from the specification’s examples. “A skilled artisan, viewing the written description as a whole, could readily differentiate between a ‘resilient’ outer catheter and a ‘pliable’ inner catheter.” Id. at *16.

The Federal Circuit found that extrinsic evidence in the form of dictionary definitions also supported its conclusion. Id.

Takeaways

Using words of degree arise may raise questions regarding whether a person of ordinary skill in the art could understand with “reasonable certainty” how the claim would be infringed. Relative terms such as “above,” “below,” “close,” “near,” “only,” “when,” “longer,” “shorter,” “substantial,” “insignificant,” “increase,” “decrease,” “greater,” and “lesser” must be treated as carefully as technical terms of art. This case provides a good example of a patent owner meeting the Nautilus standard of “reasonable certainty” for relative terms by providing sufficient explanation and examples in the specification.  

Clearly, an ounce of prevention in drafting the specification may be worth many pounds of cure. The practitioner’s challenge is to spot relative terms in a draft specification. If such terms do not appear to be defined in the specification, the practitioner should ask the inventor(s) what they mean to the skilled artisan generally and to the inventor(s) specifically.  It may well be that a such an investigation will satisfy the practitioner that the term is as definite as the art permits or is otherwise art-recognized. Additionally, out of an abundance of caution, the practitioner can develop and include a definition for the term or even a definitions section in the specification.

Relative terms or adjectives might be defined using ranges or a functional outcome. Further, during prosecution or litigation, an expert declaration may help explain how one of ordinary skill in the art would have understood a term.