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Patent law’s indefiniteness standards for “language of degree”
Technology and other patents often employ qualitative terms such as “best” or “optimal” — what courts call “language of degree.” As one patentee learned the hard way from the U.S. Court of Appeals for the Federal Circuit, this language can leave a patent vulnerable to being invalidated if objective boundaries for determining what’s “best” or “optimal” aren’t provided.
Invalid claim limitations
MediaPointe Inc. owned two patents for efficiently routing streamed media content over the Internet. Each described an “intelligent distribution network” that centrally manages requests for streamed media from many geographically dispersed users to mitigate bandwidth problems inherent in transmitting large volumes of data. Several of the patent claims described determining “best” or “optimal” devices or routes.
Akamai Technologies Inc. sued MediaPointe, seeking a declaratory judgment of noninfringement of the patents. MediaPointe countersued for infringement, and then Akamai counterclaimed for a declaratory judgment that the patents were invalid.
The trial court found that claim limitations using optimal or best language were invalid for indefiniteness. MediaPointe appealed to the Federal Circuit.
The court’s measured approach
Patent claims generally must inform people skilled in the relevant art (known as skilled artisans) about the invention’s scope with a reasonable certainty. If they don’t, the patent can be invalidated as indefinite.
A court won’t find a term of degree definite simply because the specification describes some standard for measuring the term’s scope. Rather, language of degree is indefinite unless, when read in light of the patent specification and the prosecution history, it provides objective boundaries for skilled artisans.
MediaPointe argued that the claims defined an objective standard for measuring what’s optimal or best because each included language requiring the use of “trace route results.” These results indicate 1) hops, or how many steps between adjacent devices (such as routers) a data stream must pass through to reach a client, and 2) latency, the time it takes for a message to reach a device from a starting point and for a response to return. The “best” route depends on hops, latency and reliability.
The appeals court found this claim requirement insufficient because it didn’t provide a reasonably clear and exclusive definition of optimal/best or provide an objective boundary. As to exclusivity, the claims required considering at least, but not only, trace route results. The claims didn’t say that the results were the only factors in determining what’s best or optimal.
The specification confirmed the absence of such a restriction. For example, it disclosed a “preferred embodiment” in which the best-performing devices could be determined with reference to “various factors” not limited to trace route results.
The court also found that the requirement to rely on trace route results wasn’t “reasonably clear.” Even if a claim term refers to certain objective measures, it said, the term is indefinite if 1) it might mean several different things, and 2) no “informed and confident choice” is available among the contending definitions.
The specification showed that hops and latency could indicate different “best” routes in a given case. But the patent provided no guidance about which measure, or combination of measures, should be relied on when they diverge.
The route to invalidity
The Federal Circuit has repeatedly held that, when multiple methods for determining whether a claim limitation is met lead to different results without guidance about which to use, the claim is indefinite. Finding that was the case here, it affirmed the trial court.
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