Abbott Laboratories Ltd v Medinol Ltd

In construing patent claims, the court must determine what the skilled person would understand the language to mean in the context of the specification. A technical term should be given its technical meaning where the patent uses it in that sense. Claim language should not be expanded merely because the specification describes broader possibilities.

For added matter, the comparison is between the disclosure of the application and the disclosure after amendment. Subject matter is added unless clearly and unambiguously disclosed, expressly or implicitly, in the application as filed. Claim scope and disclosure are distinct. A patent may cover subject matter without disclosing it.

Novelty requires prior art both to disclose subject matter which would necessarily infringe and to disclose it sufficiently for performance. Obviousness requires a structured assessment of the skilled person, common general knowledge, inventive concept, differences and obviousness.

Abbott sought declarations of non-infringement and revocation of three Medinol patents concerning coronary stents: European patents 0 846 449, 1 181 901 and 1 181 902. Medinol counterclaimed for infringement of 901 and 902 and accepted that 449 would be infringed if valid.

The dispute concerned claim construction, infringement by Abbott’s Vision, Multi-Link 8, Xience and Xience Prime stents, novelty over Lau and Burmeister, obviousness over Lau, added matter and insufficiency. The central questions included the meaning of “meander pattern”, “loop”, “disposed between”, “fixed length” and “alternating”, and whether the application disclosed in-phase first meander patterns.

1. Construction. The claims were construed through the eyes of the skilled team, comprising an interventional cardiologist and a medical device engineer. In claims 449 and 902, a “meander pattern” meant a periodic pattern about a centre line, with “centre line” bearing its technical meaning of a line of symmetry. A “loop” was identified functionally as a portion folded to provide a change in the length of the meander pattern or cell in response to forces encountered by the stent. “Disposed between” did not exclude shared members and had the same meaning for both sets of claim integers.

2. “Formed from flat metal” in claim 2 of 902 was not confined to cutting a pattern from a flat sheet and then forming a tube. Claim 1 of 449 likewise covered a tube cut from metal as well as a tube formed from sheet. “Expandable” in claim 12 of 902 meant capable of expanding in the specified direction in normal use, including on bending. By contrast, claim 1 of 901 required the second loops to widen longitudinally upon expansion of the stent, and required all relevant second loops to do so.

3. In claim 1 of 901, “comprising” retained its usual inclusive meaning. “Alternating” was interpreted flexibly enough to include the 1,1,1,2 sequence shown in the specification, but “even number” referred to the total number of first and second loops in the cell. The angled bisecting-line feature meant that the first and second loops had different orientations.

4. The application disclosed a core inventive concept involving intertwined meander patterns in which widening of the second patterns provided flexibility and compensated for contraction of out-of-phase first patterns on expansion. It did not disclose first meander patterns which were in phase. The abstract was disregarded for added-matter purposes because its purpose was technical information only.

5. Infringement. The Abbott stents did not contain the claimed meander patterns as construed. In any event, Abbott’s evidence did not establish that the relevant loops widened longitudinally upon expansion, as distinct from bending. Medinol therefore failed to prove infringement of claim 1 of 901, and none of the three patents was infringed.

6. Validity. On the assumed construction advanced by Medinol, Lau would anticipate claims 1 of 449 and 902. Burmeister would anticipate claims 1 of 449 and 902 and claim 1 of 901. The obviousness attack over Lau was finely balanced but failed: the skilled team faced several possible design routes and conflicting requirements, and there was no sufficient pointer to introducing longitudinal loops.

7. The general added-matter challenge failed because broadened claim scope did not itself establish added disclosure. However, the change in 902 from first patterns which “are” 180 degrees out of phase to patterns which “can be” so out of phase added matter. The proposed amendment restoring the original wording was permissible. The insufficiency allegation concerning fixed-length loops in 901 was not proved.

8. Orders. Patents 449 and 902 were valid, with 902 valid as amended. Patent 901 was invalid for lack of novelty over Burmeister. None of the patents was infringed.