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Expert’s “word salad” leads to tossed patent verdict
A finding of patent infringement under the doctrine of equivalents is “exceptional.”
Expert’s “word salad” leads to tossed patent verdict
You never want a court to describe your expert witness’s testimony as “word salad” — especially when particularized testimony is required to win your case. A patent owner learned this lesson the hard way when, according to the U.S. Court of Appeals for the Federal Circuit, its expert testimony fell short of that needed for an infringement claim based on the doctrine of equivalents.
Single action
NexStep owns a patent related to a “concierge device” that offers a streamlined approach for initiating technical customer support for a smart device, requiring only “a single action” from the user. The invention saves the user the time and hassle of following all the usual steps needed to call a support center and provide the necessary information to identify the malfunctioning product.
NexStep sued Comcast Cable Communications, alleging that three different tools in Comcast’s mobile smartphone application infringed its patent. Each of the tools is initiated by pressing a series of buttons on the smartphone’s display.
A jury found that the patent wasn’t literally infringed by the tools but was infringed under the doctrine of equivalents. The trial court, however, set aside the jury’s verdict. It granted final judgment of noninfringement as a matter of law, meaning that a reasonable jury wouldn’t have legally sufficient evidence to find in favor of NexStep on the question of liability under the doctrine of equivalents.
The court found that the testimony of NexStep’s expert was too conclusory to sustain the verdict. His “word salad,” it said, lacked the specificity and analysis required. NexStep appealed.
Generalized gibberish
Under the doctrine of equivalents, a product or process that doesn’t literally infringe the express terms of a patent claim can still be found infringing if there’s an “equivalence” between the elements of that product or process and the elements of the patented invention. As the appellate court noted in this case, a finding of infringement under the doctrine is “exceptional.”
Accordingly, the Federal Circuit has imposed specific evidentiary requirements on this approach to establishing infringement. First, equivalency is determined by comparing the individual elements of the accused product and process with the claimed elements of the patented invention. Second, the evidence of equivalency must be presented through the “particularized testimony of a person of ordinary skill in the art, typically a qualified expert.” Finally, the patentee must present “a meaningful explanation of why” the elements are equivalent, or “particularized testimony and linking argument as to the insubstantiality of the differences.”
NexStep’s expert opted to prove infringement under the doctrine of equivalents through the function-way-result test. This asks whether the allegedly infringing product or process performs substantially the same function in substantially the same way to obtain the same result as the patented invention.
The appellate court agreed with the lower court that the expert’s testimony was inadequate because it didn’t establish:
- What the function, way and result of both the patented device and the allegedly infringing device were, and
- Why those functions, ways and results were substantially the same.
For example, the expert never identified a particular element or elements in the Comcast device as being equivalent to the “single action” requirement in the patent.
That failure alone, the court said, was fatal to the doctrine of equivalents theory, but it was far from the only problem. The expert also didn’t explain why the function, way and result were substantially similar, instead resorting to comparing the overall similarities of the Comcast device and the invention. In addition, the Federal Circuit chided the expert for testifying that “several button presses along the way” provide the same function as the “single action,” essentially “because I said so.”
Connections count
Notably, the court rejected NexStep’s request for an “easily understandable technology” exception to the requirement for particularized testimony and linking argument. If you’re relying on a doctrine of equivalents theory, you must satisfy the requirement regardless of the technology involved.
