Of Catnic, clamps and catheters: the story of an ordinary word

"Judge gives word its ordinary meaning" was the striking headline of the IPKat's post last summer (here) on the decision of Mr Justice Mann (Patents Court, England and Wales) in Occlutech GmbH v AGA Medical Corp; Dot Medical Ltd [2009] EWHC 2013 (Ch). Well, yesterday -- while all true men were watching the world's major sports events -- all true IP enthusiasts were straining themselves to follow the decision of the Court of Appeal in this dispute, which you can find on BAILII here. In the event, the appellate court's ruling was not much more exciting than the England-Algeria football match. A court which was sadly lacking Lord Justice Jacob -- who is probably taking a little time off from his strenuous judicial responsibilities to pen some lectures for his new UCL job and to buy a jacket with leather patches at the elbows -- took not very long to dismiss the appeal. While a Court of Appeal patent judgment that runs to 60 paragraphs shows that their Lordships at least had to pause for thought before reaching their decision, tennis fans might see it as a bit of a 6-0.

Anyway, to summarise the matter: AGA made intravascular devices for treating certain medical conditions and had a patent for

"a collapsible medical device comprises a metal fabric formed of braided metal strands, the device having a collapsed configuration for delivery through a channel in a patient's body and a generally dumbbell-shaped expanded configuration with two expanded diameter portions separated by a reduced diameter portion formed between the opposed ends of the device, and clamps for clamping the strands of the opposed ends of the device".

Occlutech made patent foramen ovale (PFO) occluders for use in patients with heart defects where there were gaps in the atrial wall. The PFO occluder, introduced by a catheter or similar device, consisted of two discs -- one in each atrium -- and a thin middle section which occupied the gap in the atrial wall. This device was held in place by the natural inward 'pinching' forces exerted by the discs along its axis. During manufacture, one end of the device was closed but the other was left open, the loose ends of the device protruding through the open end but being welded to form a clot during the final part of the manufacturing process.

Occlutech sought (i) a declaration of non-infringement in respect of its PFO occluders and (ii) revocation of AGA's patent for obviousness over the prior art, this being a Boston Scientific patent for 'stents for body lumens exhibiting peristaltic' which claimed "a method for providing reinforcements to the lumen of a peristaltic organ. The stent is formed by knitting a filament into interknit loops...". AGA counterclaimed for infringement and joined Dot, the importer of Occlutech's PFO occluders, to the proceedings. It was basically accepted that, for the purposes of the proceedings, the skilled addressee was a team consisting of a medical devices engineer and a clinician.

Mann J held the patent valid but decidedly uninfringed. In reaching this decision he said that the word 'clamp' had its common meaning -- an object which exerted a physical fixing and binding force on the strands of the fabric so they did not unravel. The Court of Appeal (Lord Justices Pill and Patten, plus Sir Paul Kennedy) agreed. In their Lordships' collective view, articulated by Patten LJ:

* in AGA's patent, clamps did not include welding and soldering, as well as external devices that were physically attached to the welded ends. The skilled addressee would understand that the patent specification meant there were two separate ways to secure the loose ends of the braid, and that a clamp meant the application of an external device to hold the strands together as opposed to fusing them together with solder or a weld.

* the claims in the patent did not therefore extend to an external device attached by welding or soldering to ends that were effectively held in place by an earlier welding process; the clamp had to be the primary and effective means of securing the loose ends.

* Occlutech's devices did not contain a clamp because the strands were not clamped in the sense of being kept together, though they were kept together by a previous weld.

* the claims referred to the plural "clamps", and there was nothing that would cause the skilled addressee to take a different view from that conveyed by the natural meaning of the words of the claims -- that (i) clamps had to be attached at the opposing ends of the device, and (ii) clamps were a distinctive and necessary feature of the invention.

Says the IPKat, it's always a pleasure to be reqcquainted with the much-loved, oft-cited and greatly analysed decision of the late, lamented House of Lords in Catnic Components Ltd v Hill & Smith Ltd [1982] RPC 183 -- a decision in which the equally late, lamented Lord Diplock warned against allowing "meticulous verbal analysis" to skew the reading of a claim to a rather low-tech patent (the gist here being arguably that 'clamp' doesn't so much mean 'clamp' as 'something which has a sufficient quality of 'clampishness' to operate as a clamp). He would however love to know whether anyone has compiled a Catnic chart, tracking those decisions in which it has been cited by the winner in any dispute over claim interpretation against those decisions in which it has been cited by the loser. He suspects that the moment Catnic is mentioned, the party citing it in support of a proposition is actually flagging up the weakness of his case. Any thoughts?

Clamps here and here

Removing a clamp here and here