SCOTUS Overrules “Insolubly Ambigous” Indefiniteness Standard

Justice Ruth Bader Ginsburg.

Earlier today the United States Supreme Court handed down its decision in Nautilis Inc. v. Biosig Instruments, Inc., which dealt with the appropriate standard for indefiniteness under 35 U.S.C. 112(b). It should be noted, however, if you read the case you will see mention of 35 U.S.C. 112, ¶ 2, which was the section of 112 at issue in the case. Congress has since relabeled section 112 to sections (a) through (f). In any event, the statute at issue reads as follows: “ The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.” This is the section that defines the so-called definiteness requirement for patent claims. 

In an opinion delivered by Justice Ginsburg for a unanimous court, the Federal Circuit was overruled, although it may wind up being much ado about nothing because it seems that the Supreme Court was concerned with the language used to articulate the indefiniteness standard, not specifically whether the claims at issue were indefinite.

The patent in dispute, U. S. Patent No. 5,337,753 (’753 patent), issued to Dr. Gregory Lekhtman in 1994 and  assigned to respondent Biosig Instruments, Inc., concerns a heart-rate monitor for use during exercise. Claim 1 of the ‘753 patent covers a heart monitor, and in two places uses the term “spaced relationship.”

The particular clauses using this term were:

… 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…

(emphasis added).


The district court determined that the term was indefinite, the Federal Circuit reversed. According to the Federal Circuit, a claim is  indefinite “only when it is not amenable to construction or insolubly ambiguous.”  Under that standard, the majority determined, the  ’753 patent survived and was not indefinite. The Supreme Court characterized this test as the Federal Circuit tolerating “some ambiguous claims but not others.”

The Supreme Court did not determine whether the claims at issue were indefinite, explaining that the Court has never micromanaged the word-choices of the Federal Circuit as it has sought to define patent law doctrine, but was uncomfortable with the use of “insolubly ambiguous” because it would lead to confusion and uncertainty, and because that particular explanation could be inconsistent with the statute.

The Supreme Court specifically explained that the Federal Circuit test could lead to confusion in the district courts because the test lacks precision, which is the cornerstone of 112(b). With this in mind, the Supreme Court remanded to the Federal Circuit for determination of whether the claims were indefinite, leaving the Federal Circuit to apply the test announced.

The test for indefiniteness provided by the Supreme Court was this:

[W]e 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.

To some extent this case may be much ado about nothing, at least insofar as the parties are concerned. The Federal Circuit did rely on the intrinsic evidence (i.e., the specification and prosecution history) and did determine that one of skill in the art would  understand the meaning of the term “spaced relationship.” Therefore, at the end of the day the Supreme Court seems to have taken issue primarily with the way the Federal Circuit articulated what was perceived as a new test. The test cannot suggest that some indefiniteness is tolerable. Either a claim provides clarity and precision, or it does not. To make the determination a Court must look at the specification and prosecution history to determine whether those of skill in the art would understand the scope of the claim with reasonable certainty. That is exactly the analysis undertaken by the Federal Circuit, so don’t be shocked it the Federal Circuit comes out with the same outcome on remand, of course minus the confusing insoluble ambiguity language.


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Join the Discussion

9 comments so far.

  • [Avatar for Anon]
    June 5, 2014 09:48 am

    American Cowboy – I am not the only one this thought is appearing to – I’ve seen the same sentiment expressed on at least three other patent blogs.

  • [Avatar for Old Examiner]
    Old Examiner
    June 4, 2014 05:12 pm

    I’m amazed that this case made it to the Supreme Court. I fail to see how setting forth two electrodes being in spaced relationship is indefinite. After reading the decision, the issue shouldn’t have been a 112, 2nd issue but a 112, 1st issue since the argument was that the disclosure was silent as to parameters relating to electrode size, spacing, etc. which resulted in lack of enablement. The recitation that 2 electrodes are positioned in spaced relationship is perfectly clear.

  • [Avatar for American Cowboy]
    American Cowboy
    June 4, 2014 10:26 am

    Good one, Anon!

  • [Avatar for Anon]
    June 4, 2014 07:21 am

    Even more curious are these words by Justice Ginsburg: “and can leave courts and the patent bar at sea without a reliable compass” in light of the Supreme Court jurisprudence on 101, its refusal to provide any meaningful compass to the lower courts at the same time it refuses to let go of its dead letters and read the words of the statute without the Court’s implicit writings included.

    Since the en banc CAFC slapped the Supreme Court with the Alice decision, throwing the Court’s lack of compass back in the face of the Supreme Court, and that decision is still forthcoming, we will have to wait and see if the Supreme Court is capable of more than the “do as we say and not as we do” admonitions.

  • [Avatar for Steve]
    June 3, 2014 05:15 pm

    Curious that SCOTUS is troubled by “ambiguous” … but not by the equally-problematic “abstract.”

  • [Avatar for American Cowboy]
    American Cowboy
    June 3, 2014 10:37 am

    The fact that we must use words to define a physical thing or process inherently requires some inexactness. They say a picture is worth 10,000 words; well how about three dimensional thing… with moving parts or conditional positioning… and it must ALWAYS be confined to one sentence fragment (claims aren’t even complete sentences, for Pete’s sake!) And they are written by people who went to engineering school, not English majors.

    Give us a break already!

  • [Avatar for Paul Cole]
    Paul Cole
    June 3, 2014 06:15 am

    Is not this decision not amenable to construction and insolubly ambiguous?

  • [Avatar for Gene Quinn]
    Gene Quinn
    June 2, 2014 11:40 pm

    Patent Leather-

    I share your fear about what Alice could bring, but still can’t imagine that even SCOTUS would say software is not patent eligible when it is mentioned all over the statute as being patent eligible.

    With these two cases I kinda scratch my head. Yes, they were pro-patentee, but it seemed to me from the start that these decisions were guaranteed to be overturned. I don’t know how you can have a test that suggests that some claims that are indefinite satisfy 112. I also don’t know how you can have inducement when there is no finding of direct infringement. Perhaps that makes sense in the world we live, but it isn’t consistent with the statute and well established case law. So i actually think SCOTUS got these two cases right.

    The article on Limelight is in the books, scheduled to publish first thing in the morning on Tuesday.


  • [Avatar for patent leather]
    patent leather
    June 2, 2014 10:26 pm

    Two unanimous negative (hurtful to innovators) Supreme Court decisions today (I think Limelight is more harmful overall than this one). I’m not looking forward to Alice which should be out soon, probably another unanimous decision holding the patent invalid. Is this the Supreme Court that hates patents?