KCI Licensing Inc & Ors v Smith & Nephew Plc & Ors

A patentable invention is property capable of assignment before it is made. An enforceable pre-invention agreement may therefore make the assignee the inventor’s successor in title for priority purposes. Priority depends on substantive rights, rather than compliance with formal distinctions between legal and equitable title.

Common general knowledge requires information generally known and accepted by the bulk of those working in the relevant field. Information discovered by a routine search is not thereby common general knowledge. In assessing obviousness, the clinician’s assessment of clinical suitability may outweigh an engineer’s assessment of mechanical properties. For secondary infringement, the relevant intention is ordinarily that of the person supplied with the means.

KCI claimed infringement of two European patents concerning negative pressure wound therapy apparatus and disposable wound drainage canisters. Smith & Nephew denied infringement and counterclaimed for revocation.

The validity issues concerned entitlement to the claimed priority date, common general knowledge, and obviousness over Argenta and Karakelle. The infringement issues concerned construction of guides, deactivation of a pump, the location of a bacterial filter, and the intention required for infringement under section 60(2) of the Patents Act 1977.

1. Priority. The patents were entitled to their claimed priority date. Section 7(2) of the Patents Act 1977 treats a patentable invention as property. An enforceable term agreed with the inventor before the invention was made can transfer legal title. The confidentiality agreement therefore made KC Inc Mr Lina’s successor in title. In any event, the agreement transferred the whole beneficial interest and the right to file patent applications. The court relied on [2009] EWHC 1304 (Pat) and considered that substantive rights, rather than legal formalities, were decisive.
2. The PCT application identified Mediscus as applicant for the United Kingdom designation only. The relevant question was entitlement to the European patents, not any separate national designation. Mediscus was therefore not a co-applicant for the European patent. Even if it had been, an assignment by conduct would have been sufficient in the circumstances.
3. Common general knowledge and obviousness. The skilled team comprised a wound-care clinician and a medical-device design engineer, led by the clinician on dressing selection. Applying the structured approach in [2007] EWCA Civ 588, reticulated foam was known to exist but its use in treating patients was not common general knowledge. Gel-forming substances were also not shown to form part of the design engineer’s common general knowledge. Information which would be found by routine investigation could be considered in obviousness, but the evidence did not establish that either material would have been found by a routine search.
4. The use of reticulated foam was not obvious over Argenta because clinical suitability was paramount and the clinician would have rejected it. Including a gel-forming substance was not obvious over Argenta. The attack based on Karakelle failed because no expert evidence established that the relevant step was obvious.
5. Construction and infringement. The guide and recess limitation did not require most of the canister to be inside the housing. Deactivation included reducing the pump’s activity sufficiently to prevent further filling; switching it off was unnecessary. An outlet incorporating a bacterial filter was not confined to an outlet formed in the canister. The relevant products fell within the claims.
6. Under section 60(2) of the Patents Act 1977, the relevant intention was that of the person supplied, not the supplier. Sales of GO pumps and canisters infringed claim 5 of ‘504 where purchasers intended that the systems might be used with foam dressings. EZ canister sales infringed claims 7 and 8 of ‘950. GO canister sales did not infringe those claims because any later use with a clamp resulted from users’ own initiative after supply.

This was a first-instance trial. The judgment records that an interim injunction in these proceedings was refused by Mann J on 31 July 2009: [2009] EWHC 2143 (Pat). No appeal from that interlocutory decision is stated.