Thoratec Europe Limited v AIS GmBH Aachen Innovative Solution (Arnold J), London, UK, 28 October 2016, Neutral Citation Number: [2016] EWHC 2637 (Pat)

In this action, the Claimant (“Thoratec”) sought revocation of two patents owned by the Defendant (“AIS”). The Claimant also sought declarations of non-infringement of both patents in respect of its product, the HeartMate PHP. Arnold J. found that the relevant claims of both patents were invalid, but would have been infringed by the HeartMate PHP.

The patents in suit were EP (UK) 2,047,872 (“EP’872”) and EP (UK) 2,234,658 (EP’658”). These patents related to Ventricular Assist Devices (“VADs”), which are medical devices that assist the ventricles in the heart in circulating blood. In particular, the patents related to VADs which are inserted into the body and driven via catheters. There was little difference between the specifications of the two patents, and the claims in EP’658 were essentially the same as a subset of those in issue in EP’872. Arnold J. therefore focussed on EP’872 in his judgment.

Distinction between the inventions in the patent

The judge noted that the claims of the patents concerned technical features located at different ends of the claimed VAD. In particular, claims 1 to 18 of EP’872 were essentially concerned with features at the proximal end of the claimed VAD and claims 19 to 22, although dependent on claims 4 to 18, were concerned with features at the distal end of the claimed VAD.

Thoratec cited Lord Hoffman in Sabaf SpA v MFI Furniture Centres Ltd [2004] UKHL 45 in which he notes the importance of deciding what the claimed invention is before determining whether the invention involves an inventive step. In common with the present case, one of the questions before the Court in Sabaf was whether the features in the claims constitute a single invention or two separate inventions. Thoratec also cited the EPO guidelines which state that the test for determining whether a set of technical features is regarded as a combination of features as opposed to mere aggregation of features, is whether the “functional interaction between the features achieved a combined technical effect which is different from, e.g. greater than, the sum of the technical effects of the individual features”.

Arnold J. found that the specification supported Thoratec’s submissions that the features of claims 19-22 of EP’872 were entirely distinct from the features of claims 1-18, and the features of the two different sets of claims performed their functions independently of each other. He was not convinced by AIS’s arguments that the skilled person would consider that, taken together, both sets of features had a synergistic effect. Therefore, whilst ultimately Thoratec’s case on validity did not turn it, Arnold J. agreed that Thoratec was entitled to rely on different prior art to attack claims 21 and 22 from that used for earlier claims 4 to 18, despite claims 21 and 22 being dependent on those earlier claims.

Prior use

In addition to documentary prior art, Thoratec sought to rely on a prior use: the use of a VAD device called the Reitan Catheter Pump (“RCP”) in a study undertaken at Maastricht University Hospital in the Netherlands. This study had been reported in the journal Chest. (The study report was also pleaded as prior art and termed “Dekker” after its lead author.) AIS argued in response that under Dutch law the disclosure of the device to the study organisers was made under an implied duty of confidence.

Arnold J. noted that the position under English law was that Thoratec, as the party relying on the prior use, had the burden of proof in establishing that the prior use made the construction of the product in question available to the public, but that the evidential burden of establishing confidentiality shifted to AIS. Based on evidence of Dutch legal experts put forward by both parties, the judge held that under Dutch law there was a rebuttable presumption that research carried out for a third party by a university or other academic institution is confidential. However based on, amongst other things, fact evidence provided by Mr Dekker on the terms under which the study was carried out, the judge held that the presumption had been “firmly” rebutted.

A copy of the judgment can be found here.