“Pliable” Language Results in “Resilient” Patent Claims

| Nicole R. Townes


Before Taranto, Bryson, and Stoll.  Appeal from the U.S. District Court for the District of Minnesota.

Summary: Providing examples in the claim language and written description may provide definiteness to descriptive terms.

Niaizi sued St. Jude for infringement of its patent related to a catheter for cannulating the coronary sinus without significant manipulation.  Niaizi alleged that St. Jude both directly infringed and induced infringement. The district court determined that all but one of the asserted claims were invalid as indefinite.  Niaizi appealed the district court’s determinations as to indefiniteness and induced infringement and entry of sanctions. 

The Federal Circuit reversed the district court’s finding that the terms “resilient” and “pliable” rendered Appellant Niazi’s claims indefinite.  The Court applied the Nautilus test established by the Supreme Court to determine whether the use of descriptive terms (i.e., “resilient” and “pliable”) results in a claim that “fail[s] to inform, with reasonable certainty, those skilled in the art about the scope of the invention.”

For the term “resilient,” the Court found that the claim language and written description provided sufficient guidance that a person of ordinary skill would know that a resilient outer catheter would refer to one that has shape memory and stiffness such that it can return to its original shape. Further, the claims provided examples of resilient materials of which the outer catheter could be made (e.g., “braided silastic”).

While there was less guidance for the term “pliable,” the Court still found that the written description provided numerous examples of a “pliable” inner catheter. For example, the claims require “an inner, pliable catheter slidably disposed in the outer catheter.” Further, the specification provides the following explanation: “constructed of a more pliable, soft material such as silicone;” and without “longitudinal braiding, which makes it extremely flexible and able to conform to various shapes.”  Thus, the Court found that when read in light of the intrinsic evidence, a person of ordinary skill in the art would understand the scope of the claims and the meaning of the terms “resilient” and “pliable” with reasonable certainty.  The Court affirmed the district court’s determination as to induced infringement and entry of evidentiary sanctions.   

Editor: Paul Stewart