One of the purposes of a patent is to notify the public that certain inventions have already been claimed and that their unauthorized use could result in liability for patent infringement. But how precise — or “definite” — must the language in a patent be to provide sufficient notice?
The U.S. Supreme Court recently considered that question and ultimately rejected the Federal Circuit Court of Appeals’ answer. Instead, in Nautilus, Inc. v. Biosig Instruments, Inc., the Court issued a unanimous decision adopting a new standard for patent definiteness that raises the bar for patent holders.
Heart of the matter
Biosig Instruments holds a patent related to a heart-rate monitor used with exercise equipment. The patent asserts that previous heart-rate monitors were often inaccurate in measuring the electrocardiograph (ECG) signals that accompany each heartbeat because of the presence of electromyogram (EMG) signals generated by the user’s skeletal muscles.
EMG signals could be generated when an exerciser moves her arm or grips an exercise monitor with her hand, thereby impeding ECG signal detection. The patented invention claims to improve on previous heart-rate monitors by detecting and processing ECG signals in a way that filters out the EMG interference.
In 2004, Biosig sued Nautilus for patent infringement, alleging that Nautilus sold exercise machines with Biosig’s patented technology without obtaining a license. Biosig’s patent described, among other things, the placement of two electrodes “mounted [on a bar ] … in spaced relationship with each other” so that both electrodes would touch one hand.
The district court dismissed Biosig’s claims before trial because the term “in spaced relationship with each other” wasn’t sufficiently definite, but the Federal Circuit reversed.
Pulse of perspective
The Patent Act requires that a patent specification “conclude with one or more claims particularly pointing out and distinctly claiming” the subject that the patentee regards as the invention. A patent that fails to do so will be struck down as invalid for “indefiniteness.” A patent’s definiteness is evaluated from the perspective, at the time the patent was filed, of someone skilled in the relevant art.
The Supreme Court considered the delicate balance of how definite a patent must be to satisfy the definiteness requirement. On the one hand, it said, some modicum of uncertainty is the “price of ensuring the appropriate incentives for innovation.” The Court also noted that patents aren’t addressed to lawyers or the general public, but to those skilled in the relevant art.
At the same time, the Supreme Court recognized, a patent must be precise enough to provide clear notice of what is claimed. This way, the public knows which inventions are still unclaimed and can be pursued without risk of infringement claims.
Pumped up standard
Under the Federal Circuit’s standard, a patent claim must be “amenable to construction” (or interpretation) and not “insolubly ambiguous.” The Supreme Court, however, found this standard was more “amorphous” than the definiteness requirement allows, lacking the requisite precision. It would, the Court said: tolerate some ambiguous claims but not others, diminish the requirement’s public-notice function, and foster an “innovation-discouraging ‘zone of uncertainty.’”
Moreover, the Supreme Court said, the standard could leave courts and patent attorneys “at sea without a reliable compass.”
The Supreme Court, therefore, rejected the Federal Circuit’s approach and established a new standard for indefiniteness. The Court held that a patent is invalid for indefiniteness if its claims, read in light of both the patent specification and the history of the patent application process, fail to inform, with reasonable certainty, those skilled in the related art about the invention’s scope.
Without such a “meaningful definiteness check,” the Supreme Court found, patent applicants would have powerful incentives to inject ambiguity into their claims.
A skipped beat
The Court didn’t weigh in on whether Biosig’s patent satisfied the Patent Act’s definiteness requirement, holding only that the Federal Circuit applied the wrong standard. The Supreme Court remanded the case to the appellate court so the Federal Circuit could apply the new standard to determine whether the patent’s claims were sufficiently definite to allow the infringement case to proceed.