Abbott Laboratories Ltd v Evysio Medical Devices ULC

Patent claims must be construed purposively, but the language chosen by the patentee remains important. A feature cannot be generalised beyond the technical disclosure directly and unambiguously conveyed by the patent or priority document. For priority, the skilled person must derive the claimed subject matter, using common general knowledge, from the earlier application as a whole. Obviousness requires identification of the skilled person, the common general knowledge, the inventive concept, the differences from the prior art and whether those differences were obvious without hindsight. A combination of features may constitute one invention where the features interact and produce a combined effect. An arbitrary feature which solves no technical problem does not confer inventiveness.

Abbott sought declarations that its coronary stents did not infringe three patents held by Evysio and sought revocation of those patents. Evysio counterclaimed for infringement. The disputed products were original and modified Multi-Link Vision and Xience stents. The principal issues were construction, infringement, novelty, obviousness over Medinol and the ACS Multi-Link, priority, added matter and sufficiency.

The proceedings were first-instance patent actions in the Patents Court. The court considered claims in European Patents (UK) 0 888 093, 0 888 094 and 1 066 804, including the meaning of substantially flat apices, diametrically opposed struts, substantially complementary extension and compression, concave and convex walls, and curved flexure means between straight sections.

1. Construction. A curved or arcuate flexure means may include a generally curved structure with a straight portion, provided it performs the claimed function. Diametrically opposed struts need not be exactly 180 degrees apart and may be in different rings. Substantially complementary extension and compression means that the outside strut extends while the inside strut compresses; equal distances are unnecessary. A substantially flat apex concerns the external surface of the whole upper segment, including its shoulders.
2. Infringement. The original medium Vision products infringed the relevant claims of 093 and 804, but the modified products did not because their dimpled apices were not substantially flat. The products did not infringe 094 because their connecting walls could not be distinguished as a first concave wall and a second convex wall. The small Vision products did not infringe 093 or 804 because their flexure means were not between two straight sections.
3. Validity. The court applied the four-stage approach in Pozzoli v BDMO [2007] EWCA Civ 588 and warned against hindsight. Claim 1 of 093 was obvious over Medinol and the common general knowledge because rounding the sharp flexure corners was an obvious design modification. Claims 1 and 23 of 804 were invalid for the same reason. The attacks on 094 failed. The Multi-Link and Medinol could not be mosaicked on the evidence to establish obviousness of 093.
4. Priority and added matter. Under section 5 of the Patents Act 1977, the claimed invention had to be derivable directly and unambiguously, using common general knowledge, from the earlier application as a whole. The claims to flexure means between two straight sections and the generalised wall configuration of 804 were not so disclosed and lacked priority. The corresponding added-matter objections also succeeded or stood with the priority findings. The claims were sufficiently clear.
5. Disposition. Patents 093 and 804 were invalid, although the original medium Vision and Xience stents would have infringed them. Patent 094 was valid but not infringed.