We wish to express our congratulations to Proskauer’s appellate litigator Mark Harris, who spearheaded a significant patent litigation victory on April 27 when the Federal Circuit reaffirmed a decision vacated by the Supreme Court, ruling in favor of Biosig Instruments in what is now the leading case concerning whether patent claims are invalid as indefinite. The Am Law Litigation Daily recognized the achievement by naming Mark its “Litigator of the Week” on April 30.

The case has a long history. After Biosig previously prevailed before the Federal Circuit, Nautilus, Inc., the defendant, appealed to the U.S. Supreme Court, complaining that the Federal Circuit had applied a controversial standard that treated a patent claim as valid so long as it was not “insolubly ambiguous.” Before the Supreme Court, Mark argued that a patent claim should be held definite if “a person skilled in the art would be able to discern its meaning from the intrinsic evidence in the patent—the claim language, the specification, and the prosecution history.” Mark argued that whatever the standard, Biosig’s patent itself was valid.

The case was closely watched, but in the end, the Supreme Court adopted the standard that Mark proposed, holding that “a patent’s claims, viewed in light of the specification and prosecution history, [must] inform those skilled in the art about the scope of the invention with reasonable certainty.” Because the Federal Circuit had applied a somewhat different articulation of the standard, the Court vacated the Federal Circuit’s decision and remanded to the Federal Circuit for that court to decide whether Biosig’s patent was invalid under the differently articulated standard.

The Federal Circuit’s ruling on remand clarified that the term “reasonable certainty” focuses on whether a skilled artisan would reasonably understand the scope of the invention, and confirmed that Biosig’s patent is valid under the new standard.

The case is Nautilus, Inc. v. Biosig Instruments, Inc.  A copy of the opinion can be found here.