Examination Practice Respecting Purposive
Construction – PN2013-02

Free World Trust and Whirlpool continue to guide the
courts, with the benefit of expert testimony and cross-examination, to construe
the claim in accordance with the principles of purposive construction outlined
therein.

However, the Office considers that the application of the principles of
purposive construction discussed in Free World Trust and Whirlpool
to the examination of a patent application must take into account the role of
the patent examiner and the purpose and context of examination.

The Office takes the position that claim construction during examination
requires an examiner to interpret each claim

    1.    Using a fair, balanced and informed
approach

• In
  order to arrive at a fair, balanced and informed understanding of the
  subject-matter of a claim, it is critical that a purposive construction of the
  claim be performed considering the specification as a whole as read through the
  eyes of the person skilled in the art, against the background of the common
  general knowledge in the field or fields relevant to the invention at the time
  the application became available to the public. In Amazon FCA it was
  recognized that, 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

• Guidance
  in identifying the problem the inventors set out to address and its proposed
  solution should be found in the description, in accordance with paragraph
  80(1)(d) of the Patent Rules, and not by reference to the closest prior
  art. This identification occurs when construing the promise of the invention
  (i.e. its utility).

    3.    In the context of the application as
a whole

• While
  claim construction during examination must remain anchored in the language of
  the claims, it was reiterated in Amazon FCA that it "cannot be
  determined solely on the basis of a literal reading" of the claims
  (paragraph 43). A properly informed purposive construction must consider the
  application as a whole.

    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. However, it should be noted that while the identification of the
  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
  one can simply conclude that the essential elements of the invention are those
  that distinguish the claimed subject matter from the prior art.

    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 in
  performing the purposive construction. The initial choice of solution should be
  guided by the description, selecting the solution given the greatest emphasis
  by the inventors. If it becomes necessary to consider a different solution, the
  analysis should be undertaken anew.

Where an examiner's conclusions regarding whether a specific element is
essential are relevant to the identification of a perceived defect in the patent
application, the examiner should provide reasons to support his/her
conclusions, e.g. emphasize the identified problem and solution and those
elements essential to providing that solution.

Commentary

In our view there is some question about the propriety of CIPO mandating
the use of a problem-solution approach.  We do not see this approach
enshrined in Catnic, Freeworld or Whirlpool. On the other
hand, Prof. Siebrasse has written on his blog that he is a “bit of a fan” of the
problem-solution approach, and we are also fans of the excellent work of Prof.
Siebrasse. He notes that the problem-solution approach is supported in Canadian
case law by Wenzel Downhole Tools Ltd v National-Oilwell Canada Ltd
2011 FC 1323, 98 CPR(4th) 155, per Snider
J.  At the same time, in our view the problem-solution approach does not
seem to be directly supported by Freeworld or Whirlpool.  As
a practical path forward, it is our view that the use of the problem solution
approach may thus be a useful guideline, but that it is clearly not the only
manner in which an analysis can be performed according to the Canadian Supreme
Court; therefore, flexibility should be available to recognize the general
principles of claim construction, and a rigid adherence to the problem-solution
approach is not required under Canadian law.  We would therefore urge caution
in being overly deferential to CIPO’s guidelines given that an overly rigid
application of the problem-solution approach may lead to a result that is
inconsistent with Canadian Supreme Court precedents.