A patent claim is invalid for indefiniteness if it cannot be construed by one of ordinary skill in the art with "reasonable certainty," the U.S. Supreme Court has unanimously held in Nautilus, Inc. v. Biosign Instruments, Inc., No. 13–369 (June 2, 2014). The Court thus replaced the Federal Circuit's "insolubly ambiguous" standard, which risked creating an "innovation-discouraging 'zone of uncertainty.'"
The question in this case was the meaning of the term "spaced relationship" in the recitation in claim 1 of U. S. Patent No. 5,337,753 of "a first live electrode and a first common electrode mounted on said first half in spaced relationship with each other." The District Court had granted Nautilus' motion for summary judgment of invalidity under 35 U.S.C. § 112, second paragraph, saying that an appropriate spacing for electrodes could not be determined from the claim. The Federal Circuit reversed, saying that the phrase was not "insolubly ambiguous" because an appropriate spacing of the electrodes -- not greater than a width of a user's hands -- could be divined from the intrinsic evidence, i.e., the specification and the file history, including a re-examination proceeding.
Balancing the competing concerns of allowing innovation to be protected while not stifling innovation by allowing patents to have uncertain scope, the Court
read §112, ¶2 to require that a patent’s claims, viewed in light of the specification and prosecution history, inform those skilled in the art about the scope of the invention with reasonable certainty. The definiteness requirement,so understood, mandates clarity, while recognizing that absolute precision is unattainable. The standard we adopt accords with opinions of this Court stating that “the certainty which the law requires in patents is not greater than is reasonable, having regard to their subject-matter.”
The Court added that "[i]t cannot be sufficient that a court can ascribe some meaning to a patent’s claims; the definiteness inquiry trains on the understanding of a skilled artisan at the time of the patent application, not that of a court viewing matters post hoc." In other words, the burden seems to be on patent drafters and prosecutors to infuse patent claims with "reasonable certainty" at the time a patent application is filed, or at least by the time a patent issues.
Patent practitioners should reconsider this burden in light of Nautilus. Many patent drafters believe in following practices intended to leave patent claims as broad as possible. For example, undefined terms may be used in a specification and claims, a claimed structure may be described in the specification as "an example," etc. Although some commentators, and the Court itself, have questioned whether the new "reasonable certainty" standard of Nautilus will have a practical impact, i.e., result in more patents being held invalid for indefiniteness, certainly the case provides an invitation for district courts to do so, and raises the possibility that practices such as those just described could lead to findings of indefiniteness.
So here are some possible practices to consider in light of Nautilus: