Federal Court rekindles patent opposition obviousness

As noted previously, the decision in Austal Ships v Stena regarding the evidentiary onus placed on an opponent has made establishing lack of inventive step as part of a patent opposition very difficult. However, the recent decision in Aspirating IP Limited v Vision Systems Limited [2010] FCA 1061 appears to have breathed new life into the ground of obviousness.

Aspirating was the applicant for a patent relating to a smoke detection system. Following an opposition hearing, various amendments to the claims and an interlocutory decision regarding whether the Commissioner or a Court should determine the validity of the amended claims, the matter came before Besanko J for determination of the substantive opposition.
His Honour commenced by noting that it was well established that an opposition will be upheld only where it is practically certain that the patent if granted would be invalid. However, while the ultimate facts leading directly to a conclusion of lack of novelty or obviousness must be proved to this level, the primary facts are to be established on the balance of probabilities.

Before considering the novelty and inventive step grounds it was necessary for the Court to construe a number of terms appearing in the claims including “main duct means in the form of sampling duct means of a smoke detection system”. The construction of this feature was significant because the evidence established that at the priority date air drawn into smoke detection systems was drawn either from air-conditioning ducts or from a dedicated network of sampling pipes. Aspirating argued that the term should be interpreted narrowly as including only a smoke detection system using a dedicated network of sampling pipes whilst Vision Systems argued that a system which sampled from air-conditioning ducts was also within the scope of the claims.

Although both parties led evidence from expert witnesses as to their understanding of the term, Besanko J considered that the key to construing the term was the use of the word “means” which “directs attention, not to some inherent or innate quality of an item of plant or equipment, but to its function”. His Honour concluded that “means”:

is a word of the broadest connotation. It directs attention to the result or effect achieved by something, not the reason it was designed and built. It enables one readily to reach the conclusion that an item of plant and equipment might be used for more than one purpose … I have no difficulty in concluding that an air-conditioning duct falls within the words “main duct means … of a smoke detection system”. I do not think that the addition of the words, “in the form of sampling duct means” operate to exclude an air-conditioning duct.

On the question of novelty, the Court held that a number of prior publications anticipated various of the amended claims. Further, the Court held that a prior use also anticipated many of the claims. The prior use related to the installation of a smoke detection system at CERN in Switzerland. Whilst that use in and of itself was not part of the relevant prior art base (being a use outside the patent area), Vision Systems relied on the evidence of an expert witness who had observed and photographed the CERN system and had given presentations in Australian describing that system. Besanko J held that the display of the photographs and explanation of the system shown in them was sufficient to constitute an anticipation.

On the question of inventive step, Aspirating sought to criticise the evidence of Vision Systems’ experts on the basis that they had seen the patent specification prior to giving their evidence and were therefore tainted by hindsight. The Court was not prepared to rule the evidence as inadmissible but did find that opinion evidence as to whether the claimed invention was obvious should be given no weight. However, his Honour found that it was appropriate for the experts to give evidence as to the hypothetical question of what they would have seen as potential solutions to the problem addressed by the invention.

Besanko J characterised the problem solved by the invention as one of “filter clogging”. For many years smoke detection systems had included filters to protect the detectors, however these were prone to becoming clogged over time, reducing the effectiveness of the system and necessitating maintenance and replacement. The invention solved this problem by providing a bypass so that only a small proportion of the air from the sampling duct was passed through the filter and on to the detector.

The evidence of the experts led by Vision Systems and accepted by his Honour was that there were two broad options for solving this problem. The first was to develop a new filter medium or mechanism and the second was to employ a bypass arrangement as in the invention. Further, there was evidence to the effect that developing a new filter medium or mechanism would be time consuming and costly. By comparison the use of bypass arrangements was already known in the industry. In the circumstances, and despite conflicting evidence from the experts led by Aspirating, Besanko J concluded that:

It seems to me that it would have been very plain to a skilled worker that the filter-clogging problem could be solved by arranging for a sample of air to be taken from a main flow in a dedicated sampling pipe and passing only that smaller sample of air through a filter and detector. There was no reason to think that that solution could not be implemented and would not work.

Accordingly, the invention as claimed was held to lack an inventive step in light of the common general knowledge alone.