20 July, 2012


Wake Forest University Health Sciences v Smith & Nephew Pty Ltd (No 2) [2011] FCA 1002


In brief


  • Wake Forest University Health Sciences and KCI Medical Australia Pty Ltd were unsuccessful in a claim that Smith & Nephew Pty Ltd had infringed a patent regarding negative pressure wound therapy.
  • Dodds-Streeton J dismissed the infringement claim because the allegedly infringing foam wound dressing kits do not possess an essential integer common to all asserted claims.
  • Her Honour also upheld the cross-claim for revocation, finding all asserted claims invalid for insufficiency, failure to define the invention and lack of clarity.
  • Wake Forest University Health Sciences appeal was heard in May 2012 and judgment is reserved.


Wake Forest University Health Sciences ("WFUHS") and KCI Medical Australia Pty Ltd ("KCIMA") (collectively "KCI") sued Smith & Nephew Pty Ltd ("S&N") for infringement of Australian Patent No 674837 (the "Patent"), which claims a medical apparatus and means for negative pressure wound therapy ("NPWT").




WFUHS is the patentee of the Patent. KCIMA is the exclusive licensee of the Patent and markets and supplies NPWT apparatus and dressings under its V.A.C® trade mark in Australia. The alleged infringements related specifically to S&N's RENASYS-F® foam NPWT dressing kits ("Kits").


The the Full Federal Court's decision to overturn an interlocutory injunction restraining S&N from marketing or supplying its Kits in Australia until final trial was previously reported on 13 October 2009.




On 30 August 2011, Dodds-Streeton J delivered a decision dismissing KCI's infringement claim because the Kits do not possess an essential integer common to all asserted claims: "a screen means sufficiently rigid to prevent wound overgrowth" ("Integer"). The decision also upheld S&N's revocation cross-claim, finding that because no meaning could be attributed to the Integer, all asserted claims are invalid for insufficiency, failure to define the invention and lack of clarity.


Meaning of "screen means sufficiently rigid to prevent wound overgrowth"


Dodds-Streeton J observed that, because the Integer is a limitation of the invention by result, "a reasonable level of scientific or clinical rigour was … required to establish on the balance of probabilities the presence of the relevant functional integer in S&N's products". KCI's evidence and submissions proposed that the words "wound overgrowth" referred to a biological process known as "hypergranulation", in which granulation tissue within a healing wound grows above the level of the surrounding healthy skin. Both parties' evidence indicated that other integers of the invention claimed by the Patent are directed at healing wounds by stimulating the growth of granulation tissue. S&N's experts observed in their evidence that it would be inconsistent for the same apparatus and method to promote the formation of granulation tissue to a point where the wound is filled, but then prevent it once the granulation tissue reached skin level. Dodds-Streeton J accepted this position in holding that "hypergranulation is simply an advanced but medically and aesthetically undesirable stage in a continuum of growth of granulation tissue" which was promoted by the Patent's "methods and apparatus and is terminated or prevented, not by any component or element thereof, but by their withdrawal or removal".



Dodds-Streeton J held that KCI had not discharged its onus of establishing that S&N's products possess the Integer, which could not be said to be present given it had no meaning, and therefore no asserted claims were found to be infringed.
Section 40 grounds
Dodds-Streeton J found all asserted claims invalid for lack of clarity. As with the finding of non-infringement, this was based on the factual finding that the Integer was "meaningless and a scientific nonsense". As Dodds-Streeton J noted, "this was thus a rare case where fundamental lack of clarity in an essential integer rendered the claims invalid".
Dodds-Streeton J also found all claims invalid for lack of sufficiency, as the lack of meaning to the essential integer of a "screen means sufficiently rigid to prevent wound overgrowth" meant the invention was not "fully" described and the best method known to the patentee had not been disclosed.
Dodds-Streeton J rejected S&N's other section 40 grounds that the claims were not fairly based on the disclosure in the specification and that they failed to define the invention.
Dodds-Streeton J observed that, if S&N successfully demonstrated that the Integer had no meaning (which it did), it could not establish lack of novelty based on the three references cited ("Bag I", "Zamierowski", "Chariker/Jeter"), because none contained the Integer expressly or (as her Honour found) even implicitly. In any case, Dodds-Streeton J considered other claim integers to be absent from each of S&N's novelty references, and that none were anticipations in any event. Her Honour made the same findings in relation to the example of prior use asserted by S&N.
Much of Dodds-Streeton J's discussion of obviousness is directed towards certain prior art documents ("Johnson I" and "Johnson II") which could be taken into account as documents which could be added to the established common general knowledge of persons skilled in the relevant art in Australia at the 1991priority date. If they could, these documents would be the starting point against which the requisite inventive step would be measured and it was likely that the steps taken from Johnson I or II to get to the invention claimed in the patent would have been obvious to a person skilled in the art in Australia in 1991. However, Dodds-Streeton J found that neither Johnson I nor II could be added to the common general knowledge in this way, as they would not have been "ascertained, understood and regarded as relevant" by persons skilled in the art in Australia in 1991, and consequently these documents could not be considered in assessing inventive step. Dodds-Streeton J also noted that it was not clear from S&N's expert evidence precisely what steps they would have taken in 1991 if they had read Johnson I or II, or how they would have arrived at the patented invention. Her Honour observed that the commercial success of the V.A.C.® (which KCI claimed satisfied a "long-felt want") "fortified, but was unnecessary to, the conclusion that obviousness was not established".
Priority date
KCI sought to move the patent's priority date from 1991 (when originally filed) to 1996 (when substantially amended), which would have brought into consideration a range of new prior art (including KCI's own public use and publications) to destroy novelty. However, Dodds-Streeton J n found that the 1996 amendments did not add new subject matter or broaden the claims, and so the 1991 priority date was preserved.
Manner of manufacture
Dodds-Streeton J rejected S&N's arguments that the claimed invention amounted to no more than a new use of known products with suitable properties for such use. As in the appeal of the interlocutory decision, however, claim 49 was again held to be invalid as a "mere collocation" of integers with no functional relationship.
The decision in this case was, as her Honour noted, a "rare" outcome, as, had the integers in the cited claims in the Patent been described more clearly, it is likely that she would have found that the claims were valid and that S&N had infringed them. WFUHS has appealed this decision, but KCIMA has not. The Appeal was heard in May 2012 and judgment is reserved.
  • It is crucial that every integer in a patent claim is meaningful. 
  • Where there is potential for doubt, integers in patent claims should be expressly defined in the specification.
  • A meaningless integer cannot only hinder an infringement claim but also render the claim invalid.
For further information, please contact:
Mary Padbury, Partner, Ashurst 
Claire Roberts, Ashurst 
Duncan Longstaff, Ashurst 


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