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Canada Rejects Problem-Solution Approach For Computer Implemented Patent

The Canadian Federal Court has rejected the problem-solution approach as adopted by the Canadian Intellectual Property Office (CIPO) for assessing patentable subject matter in favor of the purposive constructive approach as set out in the Whirlpool and Free World Trust cases.

In Choueifaty v. Canada, representative independent claim 1 reads as follows:

“A computer-implemented method for providing an anti-benchmark portfolio, the method comprising: acquiring, using a computer system, data regarding a first group of securities in a first portfolio, wherein the computer system comprises a computer processor and memory coupled to said processor, identifying, using a computer system, a second group of securities to be included in a second portfolio based on said data and on risk characteristics of said second group of securities, and providing, using a computer system, the individual weightings for each of the securities in said second portfolio according to one or more portfolio optimization procedures that maximizes the anti-benchmark ratio for the second portfolio wherein the anti-benchmark ratio is represented by the quotient of: a numerator comprising an inner product of a row vector of holdings in said second portfolio and a column vector of a risk characteristic of return associated with said holdings in said second portfolio; and a denominator comprising the square root of a scalar formed by an inner product of said row vector of said holdings in said second portfolio and a product of a covariance matrix and a column vector of said holdings of said second portfolio.”

Under Section 2 of the Patent Act, only those elements in a claim identified as essential may be considered in determining whether the subject matter of that claim qualifies as an “invention.”

Under the problem-solution approach, only those claim elements that solve an identified problem may be defined as “essential.” Using this approach, it was determined that the representative claim’s “essential” elements were “directed to a scheme or rules involving mere calculations” for weighing securities. It was further determined that these “essential” elements reflected an “optimization procedure” and not a “computer implementation.” As such, the claim was found to be non-statutory.

Under the purposive constructive approach, a claim element is “essential” if (1) modifying or substituting that element changes the way the invention works and (2) the intention of the inventor, considering the express language of the claim, or inferred from it, is that the element is “essential.” Accordingly, unlike the problem-solution approach, the purposive constructive approach does not require that “essential” elements of a claim solve an identified problem.

While Choueifaty may be appealed, it may provide some clarity for patent applications in Canada that claim a computer implemented method.


Hi, I'm John

I've been practicing law for 15 years specializing in intellectual property law, including trademark, patent, and copyright law. If you have any questions just reach out and I can help.

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