Wake Forest University Health Sciences & Ors v Smith & Nephew Plc & Anor

For obviousness, the court must apply the statutory question whether the claimed invention was obvious to the skilled person, using the Pozzoli structure to identify the skilled person, common general knowledge, inventive concept and differences from the prior art. That structure frames the evaluation but does not replace the statutory test. A prior-art disclosure must be assessed with the skilled person’s common general knowledge and without an “anticipation or nothing” approach. Where the only difference is an ordinary modification of apparatus, the court must assess whether that modification required invention for the purpose taught by the prior art. Appellate intervention is justified where the trial judge has adopted an erroneous approach or failed to evaluate the evidence properly. On that basis, adhesive film and cyclically capable vacuum equipment were obvious developments of the disclosed wound-treatment apparatus.

The respondents owned or exclusively licensed European Patent EP 0 620 720, concerning apparatus for treating wounds using negative pressure, a sealing means and an open-cell polymer foam screen. The Patents Court ([2009] EWCH 908) held Claim 1 and other claims anticipated by Bagautdinov, but rejected the appellants’ obviousness challenge to Claims 4, 16 and 19. The appellants appealed on obviousness. The respondents cross-appealed on anticipation of Claim 1 and on other claims, pursuing in this court only the Claim 1 anticipation cross-appeal and later abandoning the remaining cross-appeals. The central issues were whether Claim 1 was anticipated and whether adhesive film, cyclic operation, and specified operating ratios involved an inventive step.

1. Claim 1. The appeal and cross-appeal concerning Claim 1 were dismissed. Bagautdinov disclosed the three integers of the claim: vacuum means, sealing means maintaining negative pressure by contacting the surrounding skin, and an open-cell polymer foam screen. “Maintaining” did not require maintenance of pressure over a long period. The judge was therefore correct to find anticipation.
2. Obviousness framework. The court applied the four-step Pozzoli structure ([2007] FSR 37). It identifies the skilled person and common general knowledge, the inventive concept, the differences from the prior art, and whether those differences would have been obvious. The structure places the court in the correct frame but does not itself add a gloss to the statutory question. The court must conduct an overall evaluation of all relevant circumstances.
3. Claim 4. The only material difference from Bagautdinov was using adhesive film rather than a film secured by Vaseline, salve or plaster. Adhesive surgical films were widely available and familiar in 1991. They provided a seal and reduced the risk of dislodgment. The judge had treated the case as “anticipation or nothing”, relied on an unsupported view that Bagautdinov taught an easily removable film, and failed to evaluate material evidence. The Court of Appeal was entitled to make its own assessment and held Claim 4 obvious.
4. Claims 16 and 19. Bagautdinov did not anticipate cyclic operation. However, the Gomco pump, capable of continuous or intermittent vacuum, formed part of the common general knowledge and was suitable for implementing Bagautdinov. Using it required no invention. Claim 19 added no inventive subject matter because a cyclically capable pump necessarily fell within its specified ratios, whether or not operation at those ratios was novel as a treatment method.
5. Appellate caution, as discussed in Biogen Inc. v Medeva Plc ([1997] RPC 1), did not prevent intervention where the trial judge had failed to conduct the required overall evaluation.
6. The appeal on obviousness of Claims 4, 16 and 19 was allowed. The Claim 1 appeal and cross-appeal were dismissed, as were the other cross-appeals.

• Court of Appeal (Civil Division): [2009] EWCA Civ 848. The appeal against the rejection of the obviousness challenges to Claims 4, 16 and 19 was allowed. The Claim 1 cross-appeal on anticipation and the other cross-appeals were dismissed.
• High Court of Justice, Chancery Division, Patents Court: [2009] EWCH 908. Mr Roger Wyand QC held Claim 1 and certain other claims anticipated, but rejected the obviousness challenge to Claims 4, 16 and 19.