When Barry and Wyatt Dusome first took on the Canadian Intellectual Property Office (CIPO) without legal representation, they beat long odds. We wrote about that rare victory in the area of patent eligibility. In 2025, the Federal Court found that the Commissioner of Patents had erred by failing to apply proper purposive construction to their patent application, which relates to a card game but has implications for all Computer-Implemented Inventions (CIIs). The Court ordered the Commissioner to “consider the [Patent Application] afresh based on the Amended Proposed Claims submitted by the Appellant and in accordance with these reasons.”
As observers of the Canadian patent office know, the Patent Appeal Board and the greater patent office don’t properly apply purposive construction – a technique that determines the meaning of the claims in a patent document and determines if any elements of the claims are optional. The eligibility of artificial intelligence, analytics, enterprise systems, and other software. In the just-released reconsideration, PAB rejected the application.
Timeline
“Let me explain. No, there is too much. Let me sum up.” – Inigo Montoya
- 2008: Barry and Wyatt Dusome filed Canadian application no. 2,701,028
- 2018: CIPO issued a Final Action rejecting the claims
- 2024: The Commissioner accepted the PAB’s recommendation to reject the claims. See Barry Dusome & Wyatt Dusome (Re), 2024 CACP 11 [CD 1670].
- 2025: The Federal Court returned the application to CIPO. See Dusome v. Canada (Attorney General), 2025 FC 1809 and our blog.
- 2026 March: CIPO issued a practice note, “March 2026 Practice Notice on Patentable Subject-Matter under the Patent Act”
- 2026 September: PAB again rejected the application in the to be published 2026 CACP 5.
- 2028: The patent would expire.
Why the Federal Court Intervened
The 2025 Federal Court decision is clear and well worth reading. Justice Whyte Nowak identified four major errors in the Commissioner’s earlier decision, including:
- Failure to properly construe the claims using purposive construction.
- Improper reliance on the “actual invention” test divorced from the essential elements of the claims.
- Misapplication of subject‑matter eligibility law, including reliance on Lawson instead of Shell Oil.
- Reliance on outdated decisions, including a 1999 poker‑game decision that had no bearing on the facts of the Dusome application.
The Court emphasized that purposive construction must precede and govern the subject‑matter analysis. It is not permissible to determine the “actual invention” independently of the essential elements identified through proper construction.
CIPO’s Practice Notice
The March 24, 2026 Practice Notice is worth reviewing as it does not describe anything an expert would recognize as purposive construction. It reaffirms that:
- Purposive construction must precede any validity determination, including subject‑matter eligibility.
- The subject matter of a claim must be determined on the basis of a purposive construction.
It has one strong and helpful statement about a step often omitted by PAB and sometimes even judges.
Interpreting the terms used in the claims is a key aspect of purposive construction.
The Notice is incomplete. It barely explains how to perform purposive construction. CIPO’s guidance to applicants, examiners, and the PAB does not walk through all the needed steps:
- identifying the skilled person,
- determining common general knowledge,
- construing the meaning of the terms in the claims,
- distinguishing essential vs. non‑essential elements, and
- applying Free World Trust and Whirlpool,
Instead, the Notice spends time on two issues – actual invention and physicality.
Actual invention
CIPO again adjusts purposive construction to include an actual invention analysis. The very thing they were asked not to do. They cite scant support. Western Electric Co., Inc., et al. v. Baldwin International Radio of Canada, [1934] SCR 570
And, where the language of the specification, upon a reasonable view of it, can be so read as to afford the inventor protection for that which he has actually in good faith invented, the court, as a rule, will endeavour to give effect to that construction.
And a passage from Amazon.com, Inc. v. Canada (Attorney General), 2011 FCA 328:
… the Commissioner’s identification of the actual invention [is] to be grounded in a purposive construction of the patent claims.
They missed any obvious reference in Schlumberger Canada Ltd. v. Commissioner of Patents, 1981 CanLII 4718 (FCTAD).
Physicality
What is physical is a complicated topic. Ask an expert like a physicist, and you’ll be surprised how broad the concept is. A photon with its momentum and an electron’s field are physical. In US law, physical means tangible. In Canadian law, a patent cannot be granted for “an abstract idea” or a “disembodied” invention. A physical invention is something that has
- practical application,
- physical existence, or
- manifests a discernible effect or change.
Here it is important to note that a processor-based device has a practical application, a physical existence, and, when processor-executable code is loaded in a coupled memory, the processor-based device is discernibly changed. That is, program a computer differently and it has changed either of character or of condition.
The references cited suggest the Commissioner will allow Computer-Implemented Inventions (CIIs), but the Notice hints the opposite. The Commissioner will reject claims where there is “no physicality outside of the computer system elements” as “the mere presence of the computer may not provide the necessary physicality”. and wants to see “measurement sensors that generate data“ or a “robotic actuator”.
Importantly, the Notice misses a key requirement in patent eligibility assessments “invention is more than the new knowledge and is instead a practical embodiment of the new knowledge”. See Shell Oil.
Reading this Notice, we all knew PAB would re-construe the claims to find the actual invention and call the process purposive construction. The only question was how much they would lean on “physicality”?
The Redetermination Arrives
On September 25, 2026, the Patent Appeal Board issued its final decision on the redetermination: 2026 CACP 5. The PAB followed the 2026 March practice note and concluded that the claims were not directed to patentable subject matter.
The Board’s reasoning focused on “physicality” a concept that has increasingly dominated CIPO’s subject‑matter eligibility analysis. According to the PAB, the claimed invention did not rise above the use of “well‑known tools”, and therefore lacked the requisite physicality to qualify as patentable art. In other words, even after purposive construction, the Board found no technological contribution beyond conventional card‑game mechanics and standard computerized implementations.
The PAB’s 2026 Decision: Same Movie, New Scenes, Same Ending
PAB’s 2026 redetermination included more of the motions of purposive construction but ultimately returned to familiar ground. While the Board applied a more formal purposive construction, it concluded that the essential elements still did not amount to patent‑eligible subject matter.
The Board reviewed the meaning of terms like “first buy-in bet”, “the physical number generator playing cards”, and “showdown” in Claim 1 and other terms in the dependent claims. In terms of essential elements, the Board said “all the claimed elements as purposively construed were intended to be essential”. So the game includes cards or a processor-based device to simulate the cards.
The Board’s key finding:
The invention lacked sufficient physicality beyond “well‑known tools”.
The wording is as meek as a grade 10 essay, saying the requirements “will likely not be satisfied”.
Here PAB holds that the physical elements are known. That is they hold all the elements are essential and have physicality but the parts with physicality are not new. This makes as much sense as saying you should win a hand of poker because your rolled well at the neighbouring craps table. That is the PAB is saying it is not enough to have essential physical elements in your claims then also must be the point of novelty.
This reasoning mirrors recent PAB decisions in CII cases, including the Benjamin Moore colour‑picker applications, where even software that produces real‑world, technical effects has been deemed insufficiently physical. (See 2025 CACP 9 and 2025 CACP 10 .)
The Dusome decision reinforces the reality that, even after Choueifaty and the Federal Court’s repeated interventions, CIPO’s internal subject‑matter framework remains largely unchanged.
Vizinni: Construction!
Montoya: That word I do not think it means what you think it means.
It would seem inconceivable that CIPO keeps erring in claim construction. But this is common, and it affects anyone seeking patents in machine learning, software, and the like. One piece of progress is that PAB is actually construing the terms of the claim to give them meaning.
Why This Matters
This outcome will surprise few who follow CIPO’s treatment of CIIs. The pattern is familiar:
- CIPO misapplies the law.
- The applicant appeals.
- The Federal Court corrects the legal error and sends the case back.
- The PAB re‑rejects the application on new or reframed grounds.
So Dusome now joins Choueifaty and Benjamin Moore, where the Federal Court has intervened, and the outcome is unchanged. Amazon is a rare case of a patent being granted.
The one bright spot in the redetermination is that the panel construed the terms in the claim instead of jumping to the essential versus non-essential analysis. However, appears to have been to support a finding of non-physicality.
What Can You Do?
We suggest you hire a Canadian patent agent with expertise in claiming Computer-Implemented Inventions (CIIs). If you can’t hire us, then hire a Canadian patent agent.
Having an IP plan that considers the implications of patent eligibility on your portfolio is often more important than conducting a landscape search.
The Neverending Movie
You can rewatch some movies like “The Princess Bride”, referenced above, and others you can’t. This one is on repeat, and nothing is good.
The Dusome saga highlights several ongoing issues in Canadian patent practice:
- CIPO is willfully perverting purposive construction despite clear judicial guidance.
- CII applicants face systemic hurdles, even when their claims are drafted to emphasize technical contributions.
- Federal Court victories do not guarantee allowance, as the PAB often reframes its reasoning on remand.
- Physicality continues to dominate eligibility analysis, even though the Shell Oil test does not require physicality of the new contribution to the art.
The law is that the Commissioner must consider if the essential elements of the claim form a “practical embodiment of the new knowledge” and PAB’s practice is to ask if the novel contributions have physicality. This is wrong in so many ways.
Don’t Go Alone
It is hard to get patent protection for software‑related inventions in Canada.
The Dusome story illustrates both inventors’ resilience and the entrenched nature of CIPO’s approach to CIIs. For applicants, it underscores why careful drafting, strategic claim framing, and a deep understanding of purposive construction are essential when navigating patent eligibility in Canada’s patent office.
If you’re considering protecting a software‑related invention, please contact us.
