The High Court has found that four designs of coronary stent sold by Abbott defendants did not infringe a patent held by Medinol Limited, concluding that the designs lacked the patent’s claimed meander patterns and single-loop arrangement.
In a judgment delivered on 10 March 2011, Mr Justice Brian J. McGovern said the case concerned European Patent (IE) No. 181 902, described as a “flexible, expandable stent”. Medinol alleged that the defendants infringed the patent through their Vision, Multi-link 8, Xience and Xience Prime stents. The defendants denied infringement and counterclaimed to revoke the patent for lack of novelty, obviousness and added matter. Medinol also made a contingent application to amend the patent.
The court considered four underlying designs, as the Xience products shared the designs of Vision and Multi-link 8 products, with a drug-containing coating. Medinol argued that the stents contained two intertwined meander patterns, including loops that improved flexibility and compensated for shortening during expansion. The defendants said their stents instead had undulating rings joined by offset links.
The judge construed the patent claims in light of the specification and drawings. He concluded that a skilled reader would understand “meander pattern” as a periodic pattern about a centre line, with the patterns in the patent symmetrical and extending in different directions. The Abbott designs were intentionally asymmetric, with long and short crests, and did not contain the claimed second meander pattern. The judge also found that they lacked the required single loop of each second meander pattern between neighbouring first meander patterns. He concluded that the products did not infringe the patent.
On the defendants’ counterclaim, the judge made no finding on whether the patent was obvious over Lau or anticipated by Lau. He said the evidence was inconclusive and somewhat coloured by hindsight. He rejected the challenge based on Burmeister, concluding that it did not anticipate Claim 1 because its relevant second meander pattern was asymmetric under the construction adopted in the judgment.
The judgment records the infringement ruling and those conclusions on the counterclaim. It does not state in the supplied text a final order on revocation or Medinol’s contingent amendment application.