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From Intellectual Property Law Daily, September 29, 2017

Noninfringement judgment in coronary stent patent dispute affirmed

By Thomas Long, J.D.

Substantial evidence supported a jury’s determination that medical device makers Boston Scientific Corp. and Scimed Life Systems, Inc. (together, "BSC") did not literally infringe a patent by selling certain coronary stents, the U.S. Court of Appeals for the Federal Circuit has held. In addition, the district court properly vacated the jury’s finding of infringement under the doctrine of equivalents because the patent holder did not meet his burden of proving that his infringement theory did not "ensnare" the prior art, as he failed to draft a proper hypothetical claim. Accordingly, the appellate court affirmed the district court’s entry of judgment of noninfringement in favor of BSC (Jang v. Boston Scientific Corp., September 29, 2017, Chen, R).

At issue in this case was U.S. Patent No. 5,922,021, owned by Dr. G. David Jang, The ’021 patent was generally directed to a coronary stent. The stent disclosed by the ’021 patent involved expansion columns made up of a plurality of pairs of expansion struts, with a central column made up of connecting struts. Each connecting strut had a section at the proximal end that connected to an expansion strut pair in one expansion column; a section at the distal end that connected to an expansion strut pair in another expansion column; and an intermediate section that was not parallel to the two end sections. Each connecting strut linked expansion strut pairs from two expansion columns in a "peak-to-peak" configuration. The connecting struts were designed to increase the longitudinal flexibility of the stent.

BSC sold a product known as the Express stent, which comprised two types of alternating columns or "elements"—referred to as "macroelements" and "microelements"—that were joined together. Microelements were smaller and narrower than the macroelements on either side of the microelements. The microelements included horizontal bars that joined the microelements and the macroelements together in a "peak-to-valley" configuration.

In 2002, Jang assigned his rights in the ’021 patent to BSC in exchange for an upfront payment of about $50 million and a conditional promise to make additional payments for the sales of stent products that were covered by the assigned patents. In 2005, Jang sued BSC, asserting that the Express stent was covered by the assignment agreement and infringed two claims of the ’021 patent. After litigating the case for several years, the parties proceeded to trial on the question of whether the Express stent infringed the asserted claims. Before trial, BSC moved in limine to preclude Jang from presenting a doctrine of equivalents theory. The court denied this motion, but it decided to conduct a post-trial hearing regarding BSC’s assertion that Jang’s doctrine of the equivalents theory would ensnare three prior art patents. The jury found no literal infringement but was persuaded by Jang’s doctrine of the equivalents argument and returned a verdict of infringement on that basis.

At the post-trial ensnarement hearing, Jang elected to use a hypothetical claim analysis to establish a range of equivalents to which he believed he was entitled. That is, he attempted to construct a hypothetical claim that would be broad enough to literally cover BSC’s Express stent, but not so broad that it would be unpatentable over the prior art. The district court concluded that Jang failed to draft a proper hypothetical claim as required for the ensnarement analysis. One proposed hypothetical claim impermissibly narrowed representative claim 1 of the ’021 patent, in the district court’s view, and another hypothetical claim failed to broaden claim 1 at all. Therefore, the district court vacated the jury verdict of infringement under the doctrine of equivalents and entered judgment of noninfringement in favor of BSC. Jang moved for judgment as a matter of law or a new trial as to literal infringement, which was denied. He then appealed both post-trial rulings.

Literal infringement. It was undisputed that the Express stent’s macroelements literally met all expansion column-related limitations of claim 1 of the ’021 patent. The parties disagreed, however, as to whether the jury had a reasonable basis to find that the Express stent’s microelements do not meet all connecting strut-related limitations in the claim. The Federal Circuit held that the evidence before the jury was sufficient to support its verdict. The district court did not fail to consider Jang’s argument that the Express stent’s microelements could be both expansion columns and connecting strut columns, and it correctly found substantial evidence to support the jury’s finding that the Express stent’s microelements did not meet the connection-strut-column-related limitations in claim 1. Expert testimony supported this conclusion. Moreover, the Express stent’s macroelements and microelements were joined together in a "peak-to-valley" configuration by a connecting strut with a parallel intermediate section—that is, a straight, horizontal connector—as opposed to the claimed expansion columns that were joined in a "peak-to-peak" configuration by a connector with a nonparallel intermediate section. Therefore, there was no basis to order a new trial.

Ensnarement. The Federal Circuit noted that the jury’s finding that the Express stent satisfied each claim element of the asserted claims under the doctrine of equivalents was not on appeal. Instead, the appeal centered on the district court’s application of a limitation on the reach of the doctrine, known as "ensnarement." Jang argued that his hypothetical claims were broader than claim 1, and even if they were flawed, the district court was required to proceed with an ensnarement analysis, even if that meant the district court would have to devise an acceptable hypothetical claim for Jang. The Federal Circuit rejected Jang’s arguments.

A doctrine of equivalents theory cannot be asserted if it will encompass—or "ensnare"—the prior art. This limitation applies even if a jury finds equivalence as to each claim element. When a patentee posits a hypothetical claim in support of a doctrine of the equivalents infringement theory, if that claim would have been allowed by the USPTO over the prior art, then the prior art does not bar the application of the doctrine. According to the appellate court, the district court correctly concluded that the two hypothetical claims at issue were flawed and properly declined to conduct any hypothetical claim analysis as a result.

The first hypothetical claim was broader than claim 1 because it deleted that claim’s non-parallel intermediate section limitation (thereby encompassing connecting struts with a parallel intermediate section); however, it also was narrower because it added a requirement that the connecting strut column must provide more flexibility as compared to the expansion columns. A patentee may not add any narrowing limitations to a hypothetical claim, the court said. Therefore, this hypothetical claim was properly rejected.

The appellate court agreed with the district court that the second did not broaden claim 1 at all. The addition of the words "at least" was redundant with claim 1’s use of the word "comprising," in the Federal Circuit’s view. The hypothetical claim and claim 1 had the same claim scope, the court determined. Because Jang failed to submit an acceptable hypothetical claim for consideration, he could not establish that his infringement theory did not ensnare the prior art, and the district court correctly vacated the jury verdict of infringement under the doctrine of equivalents. Jang also failed to persuade the appellate court that procedural deficiencies required reversal of the district court’s ruling.

The case is Nos. 2016-1275 and 2016-1575.

Attorneys: Daryl Joseffer (King & Spalding LLP) for G. David Jang, M.D. Matthew Wolf (Arnold & Porter Kaye Scholer LLP) for Boston Scientific Corp. and Scimed Life Systems, Inc. n/k/a Boston Scientific Scimed, Inc.

Companies: Boston Scientific Corp.; Scimed Life Systems, Inc. n/k/a Boston Scientific Scimed, Inc.

MainStory: TopStory Patent FedCirNews

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