Edwards Lifesciences Corporation & Anor v Meril GmbH & Anor

A patent claim must be construed as a whole, by reference to the skilled reader and the specification, without importing limitations from particular embodiments or omitted claim language. A claim to a flex-indicating delivery system required a visual indication of flex, but did not require graduated markings or particular slot positioning.

For obviousness, the court must assess the prior art and common general knowledge in their factual context. A technical concern in the prior art may motivate an obvious modification rather than deter it. Equivalence is assessed by asking whether the variant achieves substantially the same result in substantially the same way, whether that would be obvious to the skilled person, and whether strict literal compliance was intended to be essential.

The claimants, the proprietor and exclusive licensee of two prosthetic heart-valve patents, alleged that Meril’s Myval valve and Navigator delivery system infringed. Meril denied infringement and counterclaimed for revocation on grounds including obviousness, insufficiency and added matter.

The proceedings concerned EP (UK) 1 267 753, relating to an expandable prosthetic heart valve, and EP (UK) 3 494 929, relating to a delivery system with a flex-indicating device. The central issues were construction, infringement including equivalents, obviousness over the cited prior art, and added matter.

1. 753 patent. Claim 1 covered both the continuous-tube and separate-leaflet embodiments because the assembled structures each had a flexible tubular structure. The claim did not require commissure posts to cantilever. The Myval device contained a tubular base, commissure posts and a fabric section, and infringed claim 1.
2. Claim 1 was nevertheless invalid for obviousness. Starting from Cribier, with Andersen forming part of the common general knowledge and being expressly discussed in Cribier, it was obvious to use a frame with commissure posts, pericardial or porcine leaflets, and a fabric internal cover. Cribier’s criticisms of Andersen did not deter the skilled team. Some criticisms made the internal cover or a two-stage deployment approach more obvious.
3. 929 patent. The balloon catheter and guide catheter were separate and distinct elements. The reference to indicia required a visual indication of the amount of flex, but a graduated scale was unnecessary. A device indicating no flex and full flex could satisfy the requirement. The slot need only receive part of the flex-indicating member; it need not be visible or located externally.
4. The Navigator did not literally infringe claim 1 because its outer shaft was a single composite structure rather than two distinct catheters. It infringed claim 1 by equivalents. Applying Actavis v Lilly [2017] UKSC 48 and the guidance in Icescape v Ice-World [2018] EWCA Civ 2219, the Navigator achieved the same result in substantially the same way; the distinction between separate and combined catheter structures was not an essential feature.
5. Claims 1 and 2 of the 929 patent were invalid over the alternative Marchand embodiment. Claims 4, 5, 7, 8, 9, 11, 12 and 13 were independently valid. The Navigator infringed claims 4, 5, 8, 9, 12 and 13, including claim 12 by equivalents. Device B also infringed, while Device A did not.
6. The added-matter attacks were rejected. The application as filed disclosed the relevant features without an impermissible intermediate generalisation.