Digest of BIOSIG INSTRUMENTS, INC. v. NAUTILUS, INC., No. 2012-1289 (Fed. Cir. April 27, 2015) (precedential). On remand from the United States Supreme Court. Before Newman, Schall, and Wallach.

Procedural Posture: Biosig appealed the district court’s grant of summary judgment that the patent-in-suit, directed to a heart rate monitor, is invalid as indefinite. In a prior decision, the CAFC held the claims were not invalid for indefiniteness, applying the “not amenable to construction” and “insolubly ambiguous” standard. The Supreme Court granted certiorari, and vacated and remanded the CAFC’s decision. On remand, under the “reasonable certainty” standard, the CAFC again held the claims definite.

  • Indefiniteness: The Supreme Court’s “reasonable certainty” standard for indefiniteness is a balance between permitting a modicum of uncertainty in language to ensure incentives for innovation and providing enough precision to afford clear notice of what is claimed. The claim term ‘spaced relationship’ was found to be definite based on the claim language, specification, and figures, as well as the prosecution history in the reexamination and an inventor declaration, because it informs a skilled artisan with reasonable certainty of the scope of the claim.
  • Claim Construction: Claim construction is a legal question reviewed de novo, while underlying factual determinations made by the district court based on extrinsic evidence are reviewed for clear error, in accordance with the Supreme Court’s decision in Teva Pharmaceuticals USA v. Sandoz (2015). In this case, construction was based on primarily intrinsic evidence, and was reviewed de novo.