Federal Court Rejects Patent Office’s Approach to Claim Construction: Music to the Ears of Patentees in the Medical Diagnostic and Computer-Related Fields

August 27, 2020
By Melanie Szweras, Paul Horbal and Ray Kovarik

The Canadian Intellectual Property Office’s (CIPO) approach to the question of patentable subject matter – what can be patented – has been much-criticized in recent years as departing from that which is required in law. In upholding an appeal by in 2011, the Federal Court of Appeal ruled that CIPO’s attempts to use a “substance of the invention” test of its own creation was “incorrect in law.” Rather, the Court made clear that “determination of subject matter must be based on a purposive construction of the patent claims.” Nevertheless, CIPO in the intervening years has directed its patent examiners to use yet another, novel “problem-solution” approach to claim construction as a required step when considering the issue of patentable subject matter. This approach, while couched in the language of purposive construction, differs markedly from that test as defined by the Supreme Court of Canada in two landmark decisions.1 Now, the Federal Court of Canada has given hope to prospective patentees – particularly those in the life sciences and computer industry – that CIPO may finally adopt a consistent claim construction approach in accordance with established case law.

On August 21, 2020, the Federal Court of Canada handed down its ruling in the appeal of Yves Choueifaty against the rejection of his application by the Commissioner of Patents (Yves Choueifaty v. Attorney General of Canada, 2020 FC 837, [Choueifaty]). Choueifaty had argued that CIPO was wrong to use the problem-solution approach in construing its patent claims. Ruling in Choueifaty’s favour, the Court found that the Commissioner of Patents had indeed “erred in determining the essential elements of [Choueifaty’s] claimed invention by using the problem-solution approach,” rather than the approach the Supreme Court has directed to be used, in particular, one that considers the inventor’s intention and the words of the claim. It remanded the application to CIPO, to perform a fresh assessment of the claims in view of the decision.

As noted above, the Supreme Court of Canada has set out the principles of purposive construction to be used when construing patent claims. Among other steps, purposive construction requires establishing whether particular claim elements should be considered essential or non-essential. CIPO’s problem-solution approach seized on this wording in an attempt to exclude elements from consideration, unless they are deemed essential to solving the problem faced by the applicant. CIPO’s approach thus allowed a patent examiner to disregard certain claim elements even in cases where the applicant insisted that they were indeed essential to the invention. It justified this departure by relying on a 2008 Federal Court decision, which it argued held that the Supreme Court’s direction regarding purposive construction applied only to court proceedings involving issued patents, and not the examination of patent applications.2 The decision in Choueifaty firmly rebukes this position.

Although the ruling in Choueifaty has implications in all cases where purposive construction is to be used during examination, it has particular importance with respect to the question of patentable subject matter. CIPO’s problem-solution approach has created great difficulty for computer-based and medical diagnostic inventions. For example, in computer-related cases, patent examiners will often characterize the alleged “problem” in such a manner that any computer elements recited in a claim are non-essential and can be disregarded. Once the computer elements are disregarded, what remains is easily classified as an abstract idea or mere scheme and thus the entire invention is excluded from patentability. Similarly, in medical diagnostic cases, patent examiners often determine that the innovation is directed to the discovery of a correlation between a genetic alteration, or a level of an analyte, and a disease or other medical condition. Once the elements of measuring or detecting the genetic alteration or analyte are disregarded, the claim is alleged to be directed to a disembodied idea (i.e. a mental process or having no practical application) and, again, excluded from patentability.

The decision in Choueifaty rests solely on the issue of claim construction, and the Court was careful to steer clear of the thorny issue of what constitutes patentable subject matter. Nevertheless, both topics are inextricably linked. Therefore, this case will almost certainly have an immediate impact on patent prosecution, particularly in the life sciences and computer-related fields. In addition, it remains to be seen how CIPO will react to this decision. In previous instances where courts directed changes to the manner in which patentable subject matter is assessed, applicants faced lengthy examination delays while CIPO updated its approach and examiner guidance. Further appeals are also possible, and perhaps even welcome, if they will lead to new and clearer precedent that can be followed by applicants and examiners alike.

1 Free World Trust v Électro Santé Inc, 2000 SCC 66 [Free World Trust] and Whirlpool Corp v Camco Inc, 2000 SCC 67 [Whirlpool].

2 Genencor International Inc. v. Canada (Commissioner of Patents), 2008 FC 608.


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