Problem Found with Problem-Solution Approach to Claim Interpretation

In the recent Canadian Federal Court decision Choueifaty v Canada (Attorney General) 2020 FC 837 the Judge rejected the problem-solution approach to claim construction, finding that that interpretive framework can restrict the purposive construction of the claims.

Choueifaty’s patent application, titled Method and Systems for Provision of an Anti-Benchmark Portfolio, involves a computer implementation of a new method for selecting and weighing investment portfolio assets that minimizes risk without impacting returns. After the application was rejected by the examiner Choueifaty took it before the Patent Appeal Board (PAB) who considered two sets of proposed amendments, the first involving 27 claims and the second involving 63 claims. While Choueifaty argued that in the second set a computer was an essential element of the claims, the PAB found in both cases that the essential elements of the claims were directed to a scheme or rules involving mere calculations for weighing securities and involved no discernible physical effect. Consequently, on the recommendation of the PAB, the application was rejected by the Commissioner on account of being a mere plan and so not involving patentable subject matter.

In line with the Canadian Intellectual Property Office’s Manual of Patent Office Practice the purposive construction of the claims was made by identifying the problem and the solution and then determining which elements of the claims are essential to the solution provided. The Attorney General argued that this is the correct approach and arises logically from purposive construction on the basis that the purpose of the invention is to provide an operable solution to a practical problem. The Attorney General also argued that claim construction in relation to the determination of patentable subject matter is different to claim construction in relation to validity or infringement, particularly as in the latter cases the claim language has presumed validity on account of having successfully negotiated several hurdles.

However, Choueifaty argued that the problem-solution approach is not compatible with the approach to claim construction adopted in precedential Court decisions. In the Supreme Court of Canada decision Free World Trust v Électro Santé Inc, 2000 SCC 66 at [55] the test for determining whether an element of a claim is essential is whether that particular element was intended by the inventor to be essential, and whether that element could be substituted or removed without materially affecting function. In Halford v Seed Hawk Inc, 2006 FCA 275 the Federal Court of Appeal stated at [13]:

An element may be found to be essential on the basis of the intent of the inventor as expressed or inferred from the claims, or on the basis of evidence as to whether it would have been obvious to a skilled worker at the time the patent was published that a variant of a particular element would make a difference to the way in which the invention works

In Distrimedic Inc v Dispill Inc, 2013 FC 1043 the Federal Court stated at [201] “everything that is claimed is presumed essential unless the patentee establishes otherwise or the claim language otherwise dictates”.

The Judge agreed with Choueifaty, finding that the Patent Office practice on purposive construction to be wrong in distinguishing between its application to patentable subject matter on one hand and validity and infringement on the other. The Judge noted that that approach was discredited in the Federal Court of Appeal decision Canada (Attorney General) v Amazon.com, Inc, 2011 FCA 328 at [41] on the basis that in each case the focus is on the subject matter defined by the claims. The Judge further agreed that the problem-solution approach is akin to the ‘substance of the invention’ approach which was applied prior to the change to purposive construction following the UK House of Lords decision in Catnic Components Ltd v Hill & Smith Ltd, [1982] RPC 183. Whereas the problem-solution approach is useful for determining whether an element could be substituted or removed without materially affecting function, it was found to ill-equipped for determining whether a particular element was intended by the inventor to be essential. As both of those aspects of the essentiality test need to be considered, the use of the problem-solution approach to claim construction is inappropriate.

The Judge referred the case back to the Patent Office for further examination taking into account the above findings as well as considering Choueifaty’s contention that one of the purposes of the invention was to improve computer processing.

As with the decision by a Delegate of the Australian Patent Office which we recently reported, this decision should give cause for hope for business software patentees and may well feature soon in decisions on the subject matter, not only in Canada but also in Australia and New Zealand.

Author: Quinn Miller

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