Infringement
14 The fundamental issue which will arise for determination at trial goes to infringement. In the light of the statutory monopoly conferred on the holder of a patent by s 13 of the Patents Act 1990 (Cth) ("the Patents Act"), any infringement or exploitation of a patented invention is in itself a serious matter. However, that does not entail that it raises a serious question. Whether or not there is a serious question to be tried is to be determined by reference to the actual or contemplated "use" or "exploitation" by the infringer (or prospective infringer). That raises, as an anterior question, the susceptibility of the patent to impeachment on any ground, including, in this case, the grounds adverted to above.
15 As the leading authorities on exploitation of patents demonstrate, the patentee, in order to establish infringement, must show that the alleged infringer has taken each and every integer of a particular claim in the patent; see eg Populin v HB Nominees Pty Ltd (1982) 41 ALR 471 and Olin Corporation v Super Cartridge Co Pty Ltd (1977) 180 CLR 236, per Gibbs J, at 246.
16 In the Particulars of Infringement delivered with their Statement of Claim, the applicants contend that Smith & Nephew has infringed or threatened to infringe claims 1, 2, 3, 4, 6, 7, 8, 9, 24, 27, 28, 29, 36, 37, 38, 47, 48, 49, 50, 51, 52, 74, 75, 76, 84, 85, 89, 90, 91, 99, 100, 104, 108, 109, 110, 111, 112, 116, 117 and 121 of Patent No. 674837 ("the Patent"). Of those, there are seven independent "apparatus" claims and three independent "method" claims.
17 Counsel on each side tended to focus their submissions on claim 49 which is one of the independent "apparatus" claims of the Patent. It is, accordingly, useful to treat claim 49 as exemplifying the central questions to be litigated at trial. Claim 49 is in these terms;
'An apparatus for applying negative pressure to a wound beneath a fluid-impermeable seal comprising:
a screen means for positioning beneath said seal for preventing overgrowth of tissue in the wound, said screen means being sufficiently porous to allow gases to reach the wound and sufficiently rigid to prevent wound overgrowth, said screen means comprising an open cell polymer foam section configured to overlie the wound such that said negative pressure is maintained within said foam and applied to the wound;
a flexible tube having an inlet end inserted into said open cell polymer foam section and an outlet end for extending from beneath said seal and for supplying said negative pressure; and
wherein said apparatus is in an aseptic package'
18 In an affidavit sworn 19 March 2009, Gregory Richard Munt, a patent attorney retained by Smith & Nephew, has suggested that there are two alternative ways of interpreting the independent claims of the Patent, including claim 49. The first is to treat the "functional language" in the claims as limiting their scope for the purpose of assessing the validity of each claim and whether it has been infringed by a competing product or invention. That method of interpretation, according to Counsel for Smith & Nephew, entails, in order to establish validity, evidentiary demonstration, in respect of each integer, that the invention performs the function attributed to it by that integer. Thus, for example, to make out claim 49, the applicants will have to establish that the foam section comprising the "screen means" is "sufficiently rigid to prevent wound overgrowth."
19 The alternative interpretation of claims like claim 49 which has been postulated by Mr Munt involves placing "no weight whatsoever on the functional language in the claims. The consequence of this option is to greatly simplify what is covered by the claims." By way of example, Mr Munt suggests;
'16. … interpreting independent apparatus claim 49 of the Patent so that it is not confined to the functional language of the claim means that the claim defines an apparatus that comprises the following integers, with no qualifications as to the characteristics of the integers: