Canadian Patent Office Releases New Guidelines on Patentable Subject Matter

Following the recent Federal Court decision in Choueifaty v Attorney General of Canada, 2020 FC 837, the Canadian Intellectual Property Office (CIPO) has issued a Practice Notice with updated examination guidance for assessing patent-eligible subject matter.

As we discussed in our article covering the Choueifaty decision, the Federal Court held that the “problem-solution” approach previously used by CIPO to assess subject matter eligibility was not correct. In the new Practice Notice, CIPO confirms that the “problem-solution” approach should no longer be applied and outlines a new test as follows:

Purposive construction: The first step is to construe the claim in question to determine the subject matter defined by the claim. During purposive construction, the elements of the claimed invention are identified as either “essential” or “non-essential.” Non-essential elements may be varied or even omitted. Under the new CIPO guidelines, all elements set out in a claim are presumed essential, unless it is established otherwise or is contrary to the language used in the claim.

Assessment of patentable subject matter: Once the subject matter defined by a claim has been determined through purposive construction, the subject matter will be assessed for patent eligibility. To be patent eligible, the subject matter defined by the claim “must be limited to or narrower than an actual invention that either has physical existence or manifests a discernable physical effect or change and that relates to the manual or productive arts”. The “actual invention” may consist of a single element or a combination of elements that cooperate to provide a solution to a problem.

Under the old “problem-solution” approach, only elements forming the “solution” to the “problem” addressed by the claimed subject matter were considered “essential” and, thus, counted toward patent-eligibility. Elements not forming part of the “solution” were deemed “non-essential” and discounted. The “problem” and “solution” could be narrowly characterized by examiners such that computer hardware and other elements were then considered “non-essential.”

The approach set out in the new guidelines appears to be much more flexible and favorable to applicants. Under the new approach, it should be significantly harder for Examiner’s to disregard elements as “non-essential. Now, all claim elements are to be presumed essential “unless it is established otherwise or is contrary to the language used in the claim.” For example, the new guidelines state that:

An element of a claimed invention that is identified as essential for establishing the fences of the monopoly under purposive construction is not necessarily part of the actual invention. […] An element may thus be an essential element of the claim because the applicant intended it to be essential even though it has no material effect on the working of the invention.

Moreover, under the new guidelines, an essential element that would otherwise be considered patent ineligible (e.g. a disembodied idea, scientific principle or abstract theorem) may cooperate with other essential elements (e.g. those having a physical existence or manifesting a physical effect) to render the subject matter of the claim as a whole to be patent eligible.

The Practice Notice also provides several examples of the application of this test to computer-implemented inventions, medical diagnostic methods, and medical uses. In a number of examples, claims that would have likely been rejected by patent examiners under the previous guidelines are now considered to be patent eligible.

Of particular relevance to computer-implemented inventions is “Example 1” that considers the following claim (among others):

1.      A computer-implemented method of analyzing data from seismic measurements comprising:

a.       Performing seismic measurements;

b.      Receiving the data from the seismic measurements;

c.       Processing the data on a computer using algorithm X; and

d.      Displaying the results of the analysis.

Under the old “problem-solution” approach, if an Examiner considered the seismic measurements of step “a” to not form part of the solution to a narrowly characterized problem (e.g. the “problem” was not how to obtain measurements), then they might disregard step “a” as non-essential. They may similarly have deemed the “displaying” step non-essential for being a routine use for a general purpose computer. As a result, the examiner might have rejected this claim as being merely directed to a mathematical algorithm or calculations.

However, in the analysis provided in CIPO’s new guidelines, step “a” is now considered “essential” because “there is no use of language indicating that any of the steps in each claim are optional, a preferred embodiment or one of a list of alternatives”.  Since the step “includes measurements that rely upon discernible physical effects to produce their data, step a provides the discernible physical effect or change that renders the subject-matter of the claim patentable subject-matter.”

Therefore, this example suggests that claims covering computer-implemented methods that include a step of performing physical measurements may be patent-eligible, which presents a possible path forward for patent applications in this space.


CIPO’s new guidance on patentable subject matter is a welcome change, particularly to applicants who have faced challenges in pursuing applications relating to computer-implemented inventions, medical diagnostic methods, and medical uses. Although we do not yet know how the guidelines will be implemented by patent examiners, this appears to be a promising development for patentability of inventions in the software and biotechnology fields.

For more information or questions regarding patents, please contact our Intellectual Property Team.


Disclaimer: This article is to be used for educational and non-commercial purposes only. Parlee McLaws LLP does not intend for this article to be a source of legal advice. Please seek the advice of a lawyer before choosing to act on any of the information contained in this article.