In BIOSIG INSTRUMENTS, INC. v. NAUTILUS, INC., Appeal No. 2012-1289, on remand from the Supreme Court, the Federal Circuit applied the Supreme Court’s new “reasonable certainty” standard for indefiniteness and maintained the patent claims were not indefinite because the inherent parameters of the invention were provided in the intrinsic evidence. 

Biosig’s patent is directed to a heart rate monitor mounted on exercise equipment.  The claim language at issue recites “a first live electrode and a first common electrode mounted on said first half in spaced relationship with each other; a second live electrode and a second common electrode mounted on said second half in spaced relationship with each other.”  The district court granted Nautilus’s motion for summary judgment, holding that the patent was invalid because the “spaced relationship” term was indefinite.  On appeal, the Federal Circuit used the old standard that a claim is indefinite “only when it is not amenable to construction or insolubly ambiguous” and found the “spaced relationship” term to be not indefinite.

On certiorari, the Supreme Court did not express an opinion on the patent-in-suit, but vacated and remanded the case solely based on legal standard. The Supreme Court rejected the previous indefiniteness standard, and articulated a new standard that “a patent is invalid for indefiniteness if its claims read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty those skilled in the art about the scope of the invention.” Nautilus, Inc. v. Biosig Instruments, Inc. 134 S. Ct. 2120, 2124 (2014).

The Federal Circuit maintained this new standard of review is a familiar standard that has been applied by jurists all along; it is not a stricter or heightened standard as argued by the defendant.  The Federal Circuit reviewed the district court’s claim construction de novo, because only intrinsic evidence was considered. By examining the specification and prosecution history, the Federal Circuit found supporting evidence that a skilled artisan could apply a test to determine the “spaced relationship” and could determine this relationship by calculating the point in which the signals are substantially removed.  The Federal Circuit concluded a skilled artisan would understand the inherent parameters of the inventions as provided in the intrinsic evidence and would thus be informed with reasonable certainty of the scope of the claim.