PTAB v. District Court: When A Claim Is Indefinite Lacks Reasonable Certainty

In a Petition for Inter Partes Review, a petitioner may challenge patent claims as being anticipated and/or obvious. 35 U.S.C. §311(b). A challenge based on 35 U.S.C. §112, such as indefiniteness, is unavailable. However, indefiniteness may become an issue during claim construction, particularly for means-plus-function limitations.

In nearly a dozen cases, the PTAB has denied institution because it found that the petitioner did not show a limitation to be definite. In certain of those cases, the PTAB has concluded that "Petitioner has not demonstrated that the recitation of [a limitation]... viewed in light of the specification and prosecution history, sufficiently informs those skilled in the art about the scope of the invention with reasonable certainty," and thus "has not shown a reasonable likelihood that it would prevail." Medshape, Inc. v. Cayenne Medical, Inc., IPR2015-00848 (Sept. 14, 2015) (Paper 9) at 11-12. In Medshape, the PTAB applied the Supreme Court's