Note: Where any of the barristers were involved in a case reported below and the matter is still running, or potentially so, the other correspondents have taken the role of reporting that case.
Patent infringement and validity – IV catheters – “pith and marrow” test
In this proceeding, Pagone J held certain claims of two of B Braun’s patents for safety IV catheters valid and infringed by the conduct of Multigate. Both patents are for a safety needle protecting device for an intravenous catheter. Both claim the priority date of 12 June 1998 through the same chain of intermediate patents.
Pagone J was asked to consider whether the “pith and marrow” test enunciated in by Lord Cairns in Clark v Adie (1877) 2 App Cas 315 at 320 and the test enunciated by the Full Federal Court in Populin v HB Nominees Pty Ltd  FCA 45; (1982) 41 ALR 471, namely whether the infringer has taken the substantial idea disclosed by the specification and made the subject of a definite claim, was the law in Australia. Pagone J observed that Bennett J inSachtler GmbH & Co KG v RE Miller Pty Ltd  FCA 788; (2005) 221 ALR 373 had indicated that those tests were one and the same, explaining that they “apply to immaterial variations where an inessential part of step is omitted or substituted”.
Multigate contended “the question of infringement is not of taking the ‘pith and marrow’, ‘substance’ or ‘idea’ of the invention”. His Honour observed that the Full Court in Australian Mud Company Pty Ltd v Coretell Pty Ltd  FCAFC 121; (2011) 93 IPR 188, 198  had cautioned against applying the “pith and marrow” principle as extending a patentee’s monopoly to products or processes that the patentee did not, by the claims, define as the invention.
Pagone J ultimately held that: “Recourse to broad notions of the “pith and marrow”, the “substance” or “the idea” disclosed by a specification in the interpretation of a patent cannot, therefore, impermissibly enlarge a claim if not fairly made on a proper reading of the patent.
The test of infringement is whether the infringing item embodies each and every essential integer of the claim and in that task regard must be had to the terms of the claim. The application of the “pith and marrow” test must, therefore, be based on the claim in the patent. The test does not permit recourse to the substantial idea disclosed by the specification but requires that it be found in the subject of a definite claim.”
Various issues of construction arose which were crucial to Pagone’s findings on infringement. For example, the claim of the “327 Patent” required the needle to be attached to “a distal end of the needle hub”. Pagone J observed that the differences between the parties was essentially about whether the distal end was a specific point or region.
Multigate contended that the distal end of the needle hub meant “the most distal perimeter or the outer face of the needle hub which in turn meant no infringement because Multigate’s needle was not attached to the distal most face but in the central section of the needle hub. The construction advanced by Braun, in contrast, was that the words “distal end” referred to a region rather than to an end point – on that construction, Multigate’s needle was attached to a distal end of the needle hub if the distal end was, as B Braun’s expert said, any region “distal from the midpoint of the length”.
After considering the patent in detail and observing that the patent did not use the words “distal end” in the narrow way propounded by Multigate, Pagone J instead found that the words were more general and were apt in their ordinary and natural meaning to encompass the region ending with the furthest most distal point and including the area of the needle hub up to its centre.
As to another integer which required “a catheter hub attached to the proximal end of [the] catheter”, Pagone J considered that there was no need for the hub and catheter to be in direct engagement so that a ring which separated the two in one of the allegedly infringing device did not avoid infringement. Another interesting argument was whether the arms of the needle guard in the allegedly infringing devices were resiliently disposed to close over the tip of the needle or whether an elastomeric band provided that action. His Honour found that, without the elastomeric band, the arms on the needle guard of the allegedly infringing devices still blocked the needle tip as required by the claim.
Multigate asserted that the claims did not have a proper claim to priority from the parent patent application. The parent patent application referred to a great grandparent application. The great grandparent application disclosed a needle guard without crossing arms while the parent application only disclosed a needle guard with crossing arms. Multigate asserted that the parent application did not incorporate the grandparent and, as such, did not disclose a catheter with a needle guard which did not have crossing arms.
Pagone J considered that the parent incorporated the grandparent by reference (and that the skilled addressee, when reading the parent, would have sought out and obtained the grandparent in order to understand the disclosure made in the parent) and so the patents were fairly based on the parent. It should be observed that the parent application did not use any express words of incorporation of the grandparent application but referred to the grandparent in the context of identifying different configurations known. Other arguments for shifting the priority date contended for by Multigate were not accepted by Pagone J.
Multigate’s claims of lack of novelty, sufficiency and fair basis were also rejected by Pagone J. On the issue of sufficiency, B Braun asserted that Multigate’s witness was not properly qualified in that he was a user rather than designer of catheters.
Pagone J ultimately held that it was not necessary to rule upon the admissibility of his evidence but to receive it subject to the qualification of taking into account the grounds upon which it had been challenged in considering the weight it should be given. This was because the question for determination was one of fact, and the expert’s opinion, although not as an expert in design of intravenous catheters, “may assist in evaluating the evidence since the finding to be made in the case may benefit from the view of an end user able to inform the Court about how the end user understood the disclosure.”
Multigate’s claims of unjustified threats of patent infringement were, necessarily, dismissed.