Understanding Nautilus's Reasonable-Certainty Standard: Requirements for Linguistic and Physical Definiteness of Patent Claims

Authors

Gary M. Fox, University of Michigan Law SchoolFollow

Abstract

Patent applicants must satisfy a variety of requirements to obtain a patent from the U.S. Patent and Trademark Office (USPTO). The definiteness requirement forces applicants to describe their inventions in unambiguous terms so that other inventors will understand the scope of granted patent rights. Although the statutory provision for the definiteness requirement has been stable for many years, the Supreme Court’s decision in Nautilus v. Biosig Instruments altered the doctrine. The Court abrogated the Federal Circuit’s insoluble-ambiguity standard and replaced it with a new reasonable-certainty standard. Various district courts have applied the new standard in different ways, indicating the need for further clarification. This Note argues that, following the establishment of the reasonable-certainty standard, courts may understand the definiteness requirement under a two-part framework of linguistic and physical definiteness, which are both required for claims to be definite. A claim fails the linguistic-definiteness requirement if it is open to multiple constructions and one construction is not clearly correct. Additionally, a claim fails the physical-definiteness requirement if it uses comparative terms or involves ambiguous spatial relationships not limited to a narrow range.

Recommended Citation

Gary M. Fox, Understanding Nautilus's Reasonable-Certainty Standard: Requirements for Linguistic and Physical Definiteness of Patent Claims, 116 Mich. L. Rev. 329 (2017).
Available at: https://repository.law.umich.edu/mlr/vol116/iss2/4