Presumed essential: CIPO clarifies its approach toward eligibility analysis following Federal Court decision

11 November 2020

We previously reported on a recent decision of the Federal Court of Canada related to claim construction and subject-matter eligibility: Yves Choueifaty v. Attorney General of Canada [2020 FC 837 ("Choueifaty"), released August 21, 2020]. The Choueifaty decision found fault with a "problem-solution" approach to claim construction that had been applied by the Canadian Intellectual Property Office ("CIPO")[1]. Pursuant to the Choueifaty decision, which will not be appealed, CIPO has now promulgated a Practice Notice ("PN") that provides administrative guidance on claims construction and patentable subject-matter.



The PN acknowledges that Canadian claims are construed purposively, and that a purposive construction of the claims requires determining the claims' essential elements. As we discussed in our earlier article, one problem under CIPO's prior guidance was that examiners could read out explicitly recited claim elements as being "inessential", and therefore immaterial, to an eligibility analysis. In contrast, and consistent with Choueifaty, the PN is explicit that "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," and that an element may be essential "because the applicant intended it to be essential even though it has no material effect on the working of the invention." This is an approach dictated by the leading Supreme Court of Canada decisions on claims construction.[2]

Computer-implemented inventions (such as computer-implemented business methods) are discussed in the PN, with an indication that examiners should "consider whether the computer cooperates together with other elements of the claimed invention and thus is part of a single actual invention and, if so, whether that actual invention has physical existence or manifests a discernible physical effect or change and relates to the manual or productive arts." Additional commentary in the PN further emphasizes the importance of a cooperation of elements in the claimed invention in the assessment of patent eligibility. Similar to CIPO's previous guidance, the PN also notes that one factor indicative of eligibility of a computer-implemented algorithm is whether it "improves the functioning of the computer."

Medical diagnostic methods are also specifically discussed in the PN, although the Choueifaty decision itself dealt with a computer-implemented invention. The PN indicates that "a diagnostic method claim that defines a combination of elements that cooperate together so as to form a single actual invention that includes physical means for testing or for identifying, detecting, measuring, etc. the presence or quantity of an analyte in a sample would be considered to be patentable subject-matter."

A final category of subject matter discussed in the PN is medical uses, relating to the range of "use" claims that are available in Canada in place of claims to methods of treatment, which are prohibited. As a broad proposition, the PN suggests that "Where an actual invention includes one or more essential elements that comprise an active medical treatment step or surgical step or that restrict, prevent, interfere with, or require the exercise of the professional skill and judgment of a medical professional, the actual invention is an excluded method of medical treatment and is not patentable subject-matter." However, the PN goes on to adopt a flexible approach to assessing whether the professional skill and judgement of a medical professional is invoked by the claimed use, indicating that "in cases where at least one of the essential elements of the actual invention limits the claimed use to a dosage, a range of potential dosages that a patient may receive, and/or a dosage regimen, regardless of whether these are fixed and/or cover a range, this fact alone is not determinative of whether the claim is patentable subject-matter."

The new guidance from CIPO's PN is a significant departure from past practice, and should have the effect of bringing the principles applied during examination into closer alignment with the relevant jurisprudence. As we indicated with respect to the impact of the Choueifaty decision itself, there is reason to expect that this new guidance from CIPO will facilitate the recognition of eligible subject-matter related to business methods, computer-implemented inventions, diagnostic methods and medical uses.


[1] Reprising criticism from an earlier decision: Amazon.com, Inc. v. Canada (Attorney General) 2011 FCA 328; var'g 2010 FC 1011; rev'g Re Amazon.com, Inc. Patent Application No. 2,246,933 (2009) C.D. 1290, 75 CPR(4th) 85 (PAB & Com'r Pat).

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


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