The recent case Biosig Instruments Inc. v Nautilus Inc. sets a new standard for what is considered “indefinite” under U.S. patent law.

Here are the facts of the case:

Biosig Instruments, Inc., owner of a patent for a heart rate monitor, sued Nautilus, Inc. in District Court, alleging infringement of the patent. Nautilus moved to have the case dismissed, arguing that Biosig’s patent was invalid as indefinite. The District Court agreed and granted Nautilus’ motion. Biosig then appealed to the Federal Circuit which reversed the District Court’s ruling, holding that a patent claim could only be considered indefinite when the claimed subject matter is “insolubly ambiguous,” or impossible to understand for a person of ordinary skill in the relevant area. 

The case was appealed to the United States Supreme Court, which, in a landmark decision, rejected the “insolubly ambiguous” test of the Federal Circuit and adopted instead a “reasonably certainty” test. According to the Court, “a patent is invalid for indefiniteness if its claims, read in light of the specification and the prosecution history, fail to inform, with “reasonable certainty” those skilled in the art about the scope of the invention.

On remand, the Federal Circuit again reversed the District Court’s indefiniteness determination.

Thus, under the new standard, a claim is not indefinite if a skilled artisan is informed with reasonable certainty of the scope of the claimed subject matter.

Silvia Salvadori, PhD.
www.salvadorilaw.com
www.salvadorilaw.com/blog
silvia@salvadorilaw.com
(212) 897-1938