Nautilus, Inc. v. Biosig Instruments, Inc.

A patent’s indefiniteness renders it invalid if its claims fail to inform skilled artisans about the scope of the invention with reasonable certainty.

Respondent was assigned a patent for a heart rate monitor that differed from and is more accurate than previous heart rate monitors. Respondent disclosed the patented technology to a company subsequently bought out by Petitioner, and both that company and Petitioner sold exercise machines utilizing the patent without obtaining a license.

The District Court granted Petitioner summary judgment because the term, “spaced relationship” used in the patent was indefinite. The Federal Circuit reversed and remanded because the patent was not indefinite since the patent was not insolubly ambiguous. The Supreme Court vacated and remanded.

The Supreme Court held that a patent’s indefiniteness renders it invalid if its claims fail to inform skilled artisans about the scope of the invention with reasonable certainty. The Court reasoned that some uncertainly must be allowed in the patent to encourage innovation, while also being precise enough to give clear notice of what is claimed. The Supreme Court also held that the Federal Circuit’s standard did not satisfy the definiteness requirement. The Court reasoned that tolerating some ambiguous claims while rejecting others lacks the precision demanded by the statute, harming the public-notice function of the statute and discouraging innovation while leaving courts and patent bars with no reliable definiteness test.