Home » Patents » You Say “Insolubly Ambiguous,” I Say “Reasonably Certain”

You Say “Insolubly Ambiguous,” I Say “Reasonably Certain”

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A Nautilus

Today on IPcopy we have a guest post from Maia H. Harris, Mark James FitzGerald, Ph.D., and Shayne Y. Huff, Ph.D of Nixon Peabody LLP on the recent Nautilus v. Biosig Instruments decision in the Supreme Court of the United States. Over to Maia, Mark and Shayne:


The United States Supreme Court Announced A New Standard For “Indefinite” Patent Claims, But It May Be Closer To The Same Old Thing

While critically important, claim construction has only infrequently received serious attention from the highest US Court.  Let’s face it – claim construction is not exactly exciting. Maybe that’s why we were all so excited here in the US on Monday, when the Supreme Court issued a decision in Nautilus v. Biosig Instruments in which it set out a purportedly new standard for determining when a claim has met the US Patent Act’s requirement that a claim be clearly defined.  The trouble is that we may have to wait a while before we figure out what that standard actually means.  

Section 112 ¶2 of the US Patent Act requires a claim to clearly define claim scope (be definite) in order to put the world on notice of what is claimed and at the same time delineate innovation opportunities. The idea is a good one: clearly defined scope permits competitors to know what will infringe the claims as well as what permissible activity lies outside the scope of the claims.

The Nautilus case arises on appeal from a decision by the lower appellate court (the Federal Circuit) that claims in Biosig’s U.S. Patent No. 5,337,753 were not invalid for “indefiniteness.”  The patent’s claims are drawn to a heart rate monitor, such as might be incorporated into an exercise machine, which measures a subject’s heart rate through a device grasped by both of the subject’s hands.  At issue is whether the claims are indefinite due to the term “spaced relationship,” used to describe the positioning of two claimed electrodes.   The specific claim language in question is:

an elongate member….

said elongate member comprising a first half and a second half;

a first live electrode and a first common electrode mounted on said first half in spaced relationship with each other;

a second live electrode and a second common electrode mounted on said second half in spaced relationship with each other

The Federal Circuit ruled that the trial court had improperly required specific distance measurements to describe the electrode positioning referred to as a “spaced relationship.”  Although the patent provided no specific definition or other guidance on how to determine the claimed “spaced relationship,” the Federal Circuit found that it implicitly described the relationship of the two electrodes based on function.  Relying on inherent functional parameters provided in the patent and in the claims (e.g., in the whereby clauses), as well as on extrinsic evidence in the form of expert testimony, the Federal Circuit found that it was within the ability of the skilled artisan to determine the metes and bounds of the “spaced relationship” through testing and tools known and available at the time of the invention.  According to the Federal Circuit, a claim meets the Patent Act’s definiteness requirement if it is “amenable to claim construction” and not “insolubly ambiguous” upon construction, such that it fails to provide sufficient particularity and clarity to inform the skilled artisans of the bounds of the claim.  E.g., Halliburton Energy Servs., Inc. v. M-I LLC, 514 F.3d 1244 (Fed. Cir. 2008).

On Monday, the Supreme Court found that the Federal Circuit’s standard for definiteness lacks the precision that is required under the Patent Act, potentially leading to confusion by the trial courts tasked with applying that standard.  In place of the “insolubly ambiguous” standard, the Court held that “a patent is invalid for indefiniteness if its claims, read in light of the specification delineating the patent, and the prosecution history, fail to inform, with reasonable certainty, those skilled in the art about the scope of the invention.” Little additional guidance was given on the definition of “reasonable certainty,” but the Court did note that the “Federal Circuit’s fuller explications of the term ‘insolubly ambiguous’ … [in Earlier Federal Circuit decisions] may come closer to tracking the statutory prescription.” The case is now remanded back to the Federal Circuit for a decision under the correct standard.

This newly articulated standard attempts to rein in the vagueness that the Court suggested permeates the Federal Circuit’s recent decisions on definiteness, possibly signifying a lack of support for the lower court’s migration toward increasingly more flexible standards. However, the Court declined to provide many specific guidelines by which to apply this test, beyond the fact that it be driven by evidence contained within the patent specification and prosecution history, and that it “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.” The Court also emphasized that patents are “not addressed to lawyers, or even to the public generally, but rather, to those skilled in the relevant art,” possibly ushering in an increased reliance on expert testimony regarding definiteness issues and claim construction.

In many practical ways, the decision seems to be more of an affirmation of the standard for indefiniteness that has long endured in American law than a rebuke of any recent or specific application of that standard by the Federal Circuit. The Court noted the delicate balance that must be struck between the inherent limitations of language and the unavoidable existence of some modicum of uncertainty recognized for some inventions, on the one hand, and the required precision needed to provide clear notice of what is claimed in order to avoid the innovation-stifling zone of uncertainty that arises from claim ambiguity, on the other hand. The Court also noted the concern raised by some that absent a meaningful definiteness check, “patent applicants face powerful incentives to inject ambiguity into their claims.” Cognizant of these competing concerns, the Court further stated that the definiteness standard, as they articulated it, “mandates clarity, while recognizing that absolute precision is unattainable.”

The Court also appears to have followed the signals it was sending during oral argument, when it seemed troubled by all of the various proposed tests offered by the parties. But exactly how much uncertainty is going to be permitted before a claim is deemed indefinite may remain unclear until further comment from the Federal Circuit. For now, we know that “the certainty which the law requires in patents is not greater than is reasonable, having regard to their subject matter.” And we also know that the Court apparently looked with some degree of favor upon the actual analysis that the Federal Circuit applied in the underlying appeal, if not the label it attached to that analysis: “[I]f reasonable efforts at claim construction result in a definition that does not provide sufficient particularity and clarity to inform skilled artisans of the bounds of the claim, the claim is insolubly ambiguous and invalid for indefiniteness.” The specific reference to consideration of the subject matter of the claims, and other explicit references to viewing the question of indefiniteness from the point of view of those skilled in the relevant art, suggests that there still is room in the Court’s newly articulated standard for flexibility in certain areas of industry. The question may become how much flexibility, and in what circumstances.

It now falls to the Federal Circuit to provide further guidance on the correct application of the newly articulated “reasonable certainty” standard. And, more specifically, to determine whether in this case the disputed claim term “spaced relationship,” when read in light of the specification and the prosecution history, gives those with skill in the relevant art the kind of “reasonable certainty” about the scope of the invention that is required.

In the meantime, patent drafters and those involved with pending US litigation should take note.  The little guidance that is contained in the Supreme Court’s decision provides yet more reason for drafters of US patent applications (whether direct or PCT) to include specific information about claim scope in the patent specification itself.  And those involved in pending US patent litigation matters should be preparing their case around Section 112 defenses early and with intense focus on both intrinsic (that related to or contained within the patent itself) and extrinsic evidence (potentially in the form of expert opinion on the viewpoint of one with skill in the relevant art). For now, the presumption of validity still applies to invalidity defenses raised during litigation based on indefiniteness – but the trend for the indefiniteness issue to be considered in full as early as a trial court’s review of claim construction will likely continue to gain steam in US trial courts as a result of this decision.  Indeed, we may begin seeing indefiniteness move up and join the ranks of written description and patentable subject matter as viable grounds for invalidity that few US practitioners would have considered were realistic primary defenses not so long ago.

A copy of the Supreme Court’s decision in its entirety is available here.

By Maia H. Harris, Mark James FitzGerald, Ph.D., and Shayne Y. Huff, Ph.D.     4 June 2014

This article is intended as an information source for clients and friends of Nixon Peabody LLP.  The content should not be construed as legal advice, and readers should not act upon information in this article without professional counsel.  This material may be considered advertising under certain rules of professional conduct.


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