Nautilus, Inc. v. Biosig Instruments, Inc. – Definiteness Now Requires Reasonable Certainty
On June 2, the Supreme Court in Nautilus, Inc. v. Biosig Instruments, Inc., No. 13-369, __ U.S. __ (June 2, 2014) (Ginsburg, J.) ruled that the prior tests for indefiniteness, insoluble ambiguity and amenable to construction, are no longer appropriate. The new test for definiteness requires reasonable certainty. Insoluble ambiguity has been the high hurdle defendants have attempted to jump for more than twelve years since the Federal Circuit introduced that phrase in Exxon Research and Engineering v. United States, 265 F. 3d 1371, 1375 (Fed. Cir. 2001). Combined with the requirement for clear and convincing evidence to invalidate a claim, indefiniteness was not often a successful defense to patent infringement allegations.

