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Nautilus, Inc. v. Biosig Instruments, Inc.

United States Supreme Court
134 S. Ct. 2120 (2014)


A patent assigned to Biosig Instruments, Inc. (Biosig) (plaintiff), disclosed a heart-rate monitor for use during exercise that filtered out interference from muscle signals when detecting heart rate. The patent described a heart-rate monitor contained in a hollow cylinder that users grip with both hands, holding one “live” electrode and one “common” electrode at the same time. Claim 1 of the patent stated that the live and common electrodes are placed “in spaced relationship with each other.” Biosig disclosed this patented heart-rate monitor technology to StairMaster Sports Medical Products, Inc. (StairMaster). Thereafter, StairMaster sold machines constructed with Biosig’s patented technology without obtaining a license to do so, a practice continued by Nautilus, Inc. (Nautilus) (defendant), after Nautilus acquired StairMaster. Biosig filed a patent infringement suit against Nautilus. Nautilus moved for summary judgment, contending that the phrase “in spaced relationship with each other” was indefinite in violation of the definiteness requirement within 35 U.S.C. § 112. The district court granted Nautilus’s motion. Biosig appealed. The United States Court of Appeals for the Federal Circuit reversed and remanded, holding that a claim is only indefinite when it is “not amenable to construction” or “insolubly ambiguous,” and finding that Biosig’s patent was not indefinite under this standard. Nautilus appealed, and the United States Supreme Court granted certiorari.

Rule of Law


Holding and Reasoning (Ginsburg, J.)

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