PTAB Adopts District Court Indefiniteness Standard

Under AIA 35 U.S.C. § 112(b), a patent 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." In determining whether a claim is indefinite under § 112(b), the U.S. Patent & Trademark Office (USPTO) has historically employed a different standard for determining indefiniteness than U.S. district courts. Under the so-called In re Packard standard, the USPTO determined indefiniteness issues based on whether the claims contain "words or phrases whose meaning is unclear." The precedential PTAB decision Ex Parte McAward clarified (albeit in a somewhat circular manner) that under this standard, "claims are required to be cast in clear—as opposed to ambiguous, vague, indefinite—terms." In contrast, district courts employ the indefiniteness standard outlined by the U.S. Supreme Court in Nautilus Inc. v. Biosig Instruments. Under the Nautilus sta