The Canadian Intellectual Property Office (CIPO) recently released two practice notices providing guidance for the construction of claims and the examination of computer related inventions. While the practice notices strive to clarify the examination procedure of patent applications following on the Federal Court of Appeal's decision in Canada (Attorney General) v. Inc. (Amazon), they raise new issues for applicants that should be carefully considered. The Amazon decision was reported in our November 2011 Blakes Bulletin.

Construction of Claims (notice 1)

In notice 1, the CIPO acknowledges that claims must be given a "purposive construction", using the principles laid out by the Supreme Court in Free World Trust v. Electro Santé Inc. and Whirlpool Corp. v. Camco Inc., and "in the context of the application as a whole". However, the notice adds that the construction of claims during examination "must take into account the role of the patent examiner and the purpose and context of examination". The notice further states that the foundation for construing the claims of an application is to be "found in submissions from the applicant and the knowledge of an appropriately experienced examiner".

According to notice 1, the purposive construction of the claims begins with identifying the problem addressed by the invention and the proposed inventive solution to such problem. This analysis also serves to identify the promise, or "promised utility" of the invention. The notice makes it clear that the step of identifying the problem and solution is to be based on the description of the application "and not by reference to the closest prior art".

Notice 1 contemplates that a claim may include solutions to more than one problem. In such instance, the notice teaches that the examination of the claim should focus on "one solution to a problem", with the selected solution being the one "given the greatest emphasis by the inventors".

Examination of Computer-Implemented Inventions (notice 2)

In notice 2, the CIPO advises that when analyzing the subject matter eligibility of a claim directed to a computer-implemented invention, the examiner must follow the same purposive construction guidelines of notice 1. Specifically, the examiner must first identify the problem addressed by the inventors and the proposed solution, based on the description of the application. Where the description explicitly defines a problem, the examination will generally proceed on such basis. However, where no explicit statement of the problem is found, the examiner may infer the problem based on any "significant focus in the description on certain details of the solution". The notice also states that when identifying the problem, the examiner may consider statements made in the background section, any object clauses or any specific needs, limitations or disadvantages of the prior art that are identified in the application.

Notice 2 draws a distinction between a problem that is a "computer problem" (i.e., a problem with the operation of a computer) and one that is "not a computer problem" (i.e., a problem whose solution may be implemented using a computer). Factors that suggest the problem is a computer problem include:

  • statements in the description detailing a specific problem with the operation of a computer
  • the solution to the problem involves a controlling chip, system component or technical architecture element
  • an emphasis in the description of deficiencies in prior computers
  • a significant level of detail in the description to technical details, such as an algorithm or logic performed by the computer.

Once the problem and solution are identified, the claims are examined to determine the essential elements recited therein. Where a "computer problem" is identified, the solution will comprise those elements that overcome the problem, including hardware or software elements. Where a computer is found to be an essential element of a construed claim, the claim will generally be considered as being directed to statutory subject matter.

However, where a non-computer problem has been identified, the examiner is instructed to carefully consider the necessity of a computer as an essential element. Further, the notice points out that, where a solution is only described in conceptual terms, the lack of specific implementation details in the claim, may imply that a claim is "merely [directed to] the idea to use a computer to carry out certain operations". In such case, a computer may not be construed as an essential element.


Under the new guidelines proposed by the CIPO, the claim construction process involves the identification of a problem addressed by the inventors and the proposed solution (i.e., the invention) to such problem. This analysis is to be based on the examiner's review of the description and without reference to the prior art. Thus, the guidelines propose a "problem/solution" analysis that differs from the approach used, for example, by the European Patent Office.

As a result of the claim construction guidelines, patent applications should be carefully drafted so as to include a clear description of the problem and the solution, independently of the prior art. The application should also not include any generalized statements that may be misconstrued to form the problem addressed by the invention.

In the case of computer-implemented inventions, the application should clearly identify a "computer problem" and a technical solution thereto. Applicants should take extra care to do the same for computer-implemented inventions related to business methods.

In cases where an application discloses more than one problem or solution, it is important to emphasize the problem/solution that is of most interest, so as to avoid an unintended interpretation of the invention by the examiner.

In the case of applications that are currently pending, applicants should ensure that any submissions steer the examiner towards to the desired problem and/or solution.

The guidelines introduced by the two practice notices may arguably create new issues during examination of patent applications. In particular, the notices may place an overly high emphasis on the examiner's expertise in assessing applications. However, it remains to be seen how individual examiners will apply the guidelines.