On June 29, 2015, the Canadian Intellectual Property Office issued guidance to patent examiners on examining patent applications for medical diagnostic methods.

On June 29, 2015, the Canadian Intellectual Property Office (CIPO) issued a guidance document for patent examiners (the “Notice”)1 on examining patent applications to medical diagnostic methods.

The Notice identifies a diagnostic method as one that “outlines a sequence of steps to be followed to extract diagnostic meaning from data”, which will often comprise steps to “acquire data about an analyte” and “analyze the significance of the acquired data”. The Notice uses the term “analyte” broadly to mean “a chemical substance or biomarker that is the subject of analysis”.

The assessment of whether a claim is directed to patentable subject matter is to be based on the essential elements as determined by a purposive construction. To initiate a purposive construction, the examiner is to identify the problem the inventor(s) set out to solve and the solution disclosed, and the Notice provides that “the identification of the problem is guided by the description and the examiner’s understanding of thecommon general knowledge in the art” [emphasis in the Notice].

The Notice provides that for diagnostic methods “it may be appropriate to consider that an inventor is generally looking to solve a “data acquisition problem” and/or a “data analysis problem””.

Where a “data acquisition problem” has been identified, the solution is provided by those elements that provide a means to acquire data about an analyte.

Where a “data analysis problem” has been identified, the solution is provided by those elements that relate to the analysis of acquired data for the purpose of providing diagnostic meaning.

According to the Notice, once the problem and solution are identified, purposive construction involves interpreting the meaning of claim terms to determine whether elements are non-essential or essential in that they provide the solution to the problem.

The Notice further provides:

Recognizing that how data is analyzed or interpreted in a diagnostic method generally has no material effect on how the data needs to be physically acquired (and vice versa), the data acquisition elements and data analysis elements in the diagnostic method claim likely will have a relationship reflecting an aggregation rather than a combination. [emphasis added]

This suggests that should an examiner deem the problem to be one of data analysis, the examiner may disregard those steps related to data acquisition for the purpose of establishing patentability.

This approach finds further support in the Notice:

If the identified problem does not relate to data acquisition then it will presumably relate instead to a “data analysis problem”. Where this is the case, the essential elements will include steps relating to the mental analysis and/or intellectual significance of the data and will likely not include any steps to acquire the data…

The Notice concludes that “(w)here a physical step of data acquisition is identified as an essential element of the construed claim, the claimed subject-matter will likely be statutory”2, but a claim construed as consisting solely of essential elements that are disembodied will be identified as defective for lack of patentable subject matter, which will “generally apply to situations where the identified solution is only provided by an element or set of elements associated with the analysis or significance of the acquired data (e.g., the correlation)”.


CIPO has advised stakeholders that examination of medical diagnostic method cases has been delayed pending the release of this Notice. As such, we now expect an influx of Office Actions rejecting cases in this art area for alleged lack of patentable subject matter. Under the approach espoused by CIPO, it will likely be necessary to characterize a patent application as providing a solution to a “data acquisition problem” in order to successfully overcome a rejection. Alternatively, it may be possible to advance other claim types (e.g. product claims) and, in this regard, Canadian law as it currently stands may be more flexible than that of the United States with respect to the patenting of “products of nature”. The Notice does not have the force of law and, depending on the rigidity with which examiners apply it, we can also expect final refusals and appeals to the Federal Court to determine the lawfulness of the approach.