04.28.15 | Federal Circuit finds Biosig’s heart monitor patent claims not indefinite

On April 27, 2015, the U.S. Court of Appeals for the Federal Circuit ruled once again in Biosig Instruments Inc. v. Nautilus Inc. that a Biosig heart rate monitor patent asserted against Nautilus is not indefinite.

The Federal Circuit heard the case on remand from the Supreme Court, which held in June 2014 that to prove a patent is indefinite, an accused infringer must only show that it fails to inform a person skilled in the art about the scope of the invention “with reasonable certainty.” Prior to the high court’s ruling, the Federal Circuit had held that a patent was not invalid as indefinite unless it was “insolubly ambiguous.”

In this opinion, the Federal Circuit said “we may now steer by the bright star of ‘reasonable certainty,’ rather than the unreliable compass of ‘insoluble ambiguity,'” but still found that Biosig’s patent was reasonably clear.

Nautilus Remand (PDF)