A Canadian Perspective on Purposive Construction: Solving a Problem with an Interesting Solution

Published March 11th, 2013

Examination Practice Guidance Respecting Purposive Construction, PN2013-02

On March 8, 2013, the Canadian Intellectual Property Office (CIPO) issued a new Practice Notice (PN2013-02) to all Canadian Patent Examiners clarifying its position with respect to patent claim construction following the public consultation on inventive concept and the Federal Court of Appeal decision in Canada (Attorney General) v Amazon.com Inc., 2011 FCA 328 [Amazon FCA].

Context for Examination

In Amazon FCA, the Court observed that during examination, Supreme Court jurisprudence “requires the Commissioner’s identification of the actual invention to be grounded on a purposive construction of the patent claims”.

In the new Practice Notice, CIPO is taking the position that the application of the principles of purposive construction discussed in Free World Trust v. Électro Santé Inc., 2000 SCC 66 [Free World Trust] and Whirlpool Corp. v. Camco Inc., 2000 SCC 67, to the examination of a patent application, must take into account the role of the patent Examiner and the purpose and context of examination.

Practice Guidelines

The new Practice Notice now requires Canadian Patent Examiners to interpret each claim based on the following guidelines:

1) Using a fair, balanced and informed approach

Purposive construction of the claim is performed on the basis of the common general knowledge of one skilled in the art, having regard to the specification as of the date the patent was published.

As recognized in Amazon FCA, during examination, the necessary foundation of knowledge for performing a purposive construction of the claims is found in submissions from the Applicant and the knowledge of an appropriately experienced Examiner.

2) Having identified the problem and solution

The invention must be disclosed (and ultimately claimed) so as to provide one skilled in the art with an operable solution to a practical problem.

Guidance in identifying the problem should be found in the specification, and not by reference to the closest prior art.  This identification occurs when construing the promise of the invention.

Thus, identification of the problem and solution informs the purposive construction of the claim.

3) In the context of the application as a whole

As reiterated in Amazon FCA, claim construction “cannot be determined solely on the basis of a literal reading” of the claim.  Purposive construction must consider the application as a whole.

As noted by the FCA, a claim-based analysis “does not mean that the Commissioner cannot ask or determine what the inventor has actually invented, or what the inventor claims to have invented.”  The Examiner must be “alive to the possibility that a patent claim may be expressed in language that is deliberately or inadvertently deceptive”.  For example “what appears on its face to be a claim for an “art” or “process” may, on a proper construction, be a claim for a mathematical formula and therefore not patentable subject matter”.

4) To determine which elements of the claim solve the identified problem

One aspect of purposive construction is the identification of the essential elements of the claim.  The identification of the essential elements of a claim cannot be performed without having first properly identified the proposed solution to the disclosed problem.  Free World Trust recognizes that non-essential elements can be identified if “at the date of publication of the patent, the skilled addressee would have appreciated that a particular element could be substituted without affecting the working of the invention”.

Although the identification of essential elements is performed “in light of the knowledge of the art at the date of the publication of the patent specification”, this does not mean that the essential elements of the invention are those that distinguish the claimed subject matter from the prior art.

Having identified the problem, solution and essential elements in the claim, an Examiner may conclude that the claim omits an essential element or includes non-essential elements.

(i)    Missing elements:  if it appears that an essential element of a claim has been omitted, the claim may be defective for lack of support and/or utility.

(ii)   Superfluous (non-essential) elements:  the mere presence of a superfluous element is not a defect, although the inclusion of such an element could render a claim defective (e.g., if its presence results in ambiguity).

Although an Examiner may find an element to be non-essential, a court may later construe it to be essential, based on Canadian jurisprudence.

5) By focusing on one solution to a problem

An invention is an element or a combination of elements that provides a solution to a problem.  Where a claim includes solutions to more than one problem it includes more than one invention.

If a claim includes solutions to more than one problem, examination should focus on one solution to a problem.  The choice of solution should be guided by the specification, selecting the solution given the greatest emphasis by the inventors.

Purposive Construction and Examiner’s Reports

Based on the new guidance, in most cases, an Examiner will automatically ascribe appropriate meanings to the terms of a claim in light of the teachings of the description and the Examiner’s technical expertise.  In such cases, it is not necessary for the Examiner to explain these conclusions in a report, unless it becomes apparent that there is some relevant disagreement between the Examiner and the Applicant.

In some cases, it will be possible for an Examiner to conclude that a claim does not comply with the Patent Act or Patent Rules without explicitly determining whether a given element is or is not essential.  Here again, Examiners are not required to detail in reports parts of their analysis that are not in issue.

However, where an Examiner’s conclusions regarding a specific element are relevant to the identification of a perceived defect, the Examiner should provide reasons to support their conclusions, e.g., emphasize the identified problem and solution and those elements essential to providing that solution.

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