Federal Circuit Reasonably Certain Biosig’s Patent Not Indefinite

John Kong | April 29, 2015

Biosig Instruments v. Nautilus

April 27, 2015

Before: Newman, Schall, and Wallach.  Opinion by Wallach.


On remand from the Supreme Court, the Federal Circuit applies the “new” indefiniteness test announced by the Supreme Court in “Nautilus II” and concludes that the disputed term “spaced relationship” in Biosig’s patent claims is not indefinite.  After a two year hiatus from the first time the Federal Circuit decided this case in April 2013 in “Nautilus I,” the Federal Circuit comes to the same conclusion as it did under the previous indefiniteness test.


The Biosig ’753 patent involves a heart-rate monitor used with exer­cise equipment.  The disputed term “spaced relationship” is used to describe the locations of a “live” electrode and a “common” electrode mounted on each half of a cylindrical bar:






The Federal Circuit acknowledged the Supreme Court faulting its previous imprecise articulation of the indefiniteness test and stated that “we may now steer by the bright star of ‘reasonable certainty,’ rather than the unreliable compass of ‘insoluble ambiguity.’”

Regarding “reasonable certainty,” the Federal Circuit noted Judge Bryson’s comments in an E.D. Tx decision, sitting by designation, that “contrary to the defendant’s suggestion, [the Nautilus II] standard does not render all of the prior Federal Circuit and district court cases inapplicable.”  In a footnote, there is a laundry list of prior Federal Circuit and the predecessor CCPA court cases applying a reasonable certainty standard.  Another footnote lists another laundry list of Supreme Court cases offering a spectrum of interpretation of “reasonable certainty” in various contexts.  Some quotes from Supreme Court cases include:

  • the requirement of reasonable certainty does not preclude the use of ordinary terms to express ideas which find adequate interpretation in common usage and understanding
  • the Court found a reasonable certainty requirement satisfied not with “mathematical exactness,” but only a “reasonable approximation”
  • a “rough estimate” does not provide the reasonable certainty required
  • reasonable certainty …goes no further than to require a basis for a reasoned conclusion
  • a reasonable certainty, founded upon inferences legitimately and properly deducible from the evidence

The Federal Circuit then proceeded to exercise the Supreme Court’s “delicate balance,” or as the Federal Circuit calls it, the “necessarily inexact balance,” between, on the one hand, “the inherent limitations of language” and “the price of ensuring the appropriate incentives for innovation” versus, on the other hand, the “modicum of uncertainty” and enough precision “to afford clear notice of what is claimed.”  In doing so, the Federal Circuit also acknowledged the Supreme Court’s new standards of review from Teva Pharmaceuticals USA v Sandoz of (1) de novo for review of claim constructions based on intrinsic evidence and (2) clear error for review of claim constructions relying on subsidiary fact findings based on extrinsic evidence, for example to understand the relevant science.  The goal, again, is to determine whether a skilled artisan would understand the scope of the invention with reasonable certainty.

Here, the Federal Circuit carefully emphasizes how its previous determinations were based solely on intrinsic evidence (the patent claims, specification, and prosecution history).  The specification, claims, prosecution history, and inventor’s testimony during a reexamination, all supported the Federal Circuit’s previous boundary determinations that “spaced relationship” between the electrodes cannot be greater than the width of a user’s hands and cannot be infinitesimally small.


Full Opinion

Subscribe | 登録



词典 / 辞書 / 사전
  • dictionary
  • dictionary
  • 英語から日本語

Double click on any word on the page or type a word:

Powered by dictionarist.com