Patentable Subject-Matter under the Patent Act

Taking into account the recent decision of the Federal Court in Yves Choueifaty v Attorney General of Canada, 2020 FC 837, this document is intended to provide guidance on the current understanding by the Patent Office of the legal principles applicable in determining whether the subject-matter defined by a claim is patentable subject-matter, particularly in respect of computer-implemented inventions, medical diagnostic methods and medical uses.

The present guidance builds on guidance in the Manual of Patent Office Practice (MOPOP).  However, it does supersede some of the guidance currently present within MOPOP.  In particular, the references in MOPOP chapters 12, 17, 18, 22 and 23,Footnote 1 to the "contribution" of a claim; to a "technological solution to a technological problem"; and, to the "problem and solution" approach in the identification of essential elements during purposive construction should no longer be applied.

Purposive Construction

The first step in determining whether the subject-matter defined by a claim is patentable subject-matter is to construe the claim.

Subsection 27(4) of the Patent Act requires that the specification end with a claim or claims defining distinctly and in explicit terms the subject-matter of the invention for which an exclusive privilege or property is claimed.

The subject-matter defined by a claim is determined on the basis of a purposive construction of the claim conducted in accordance with the principles set out by the Supreme Court of Canada in Free World Trust v Électro Santé Inc., 2000 SCC 66 and Whirlpool Corp. v Camco Inc., 2000 SCC 67.

The goal of purposive construction of a claim is to determine the fences of the monopoly claimed by the applicant.Footnote 2 This is done by objectively determining where the person skilled in the art would, as of the date of publication of the patent application and on the basis of the particular words or phrases used in the claim, have understood the applicant to have intended to place the fences around the monopoly being claimed.Footnote 3

The purposive construction of a claim is carried out in light of the whole of the specification and takes into account what the person skilled in the art would understand from the whole of the specification to be the nature of the invention.Footnote 4

During purposive construction of a claim, the elements of the claimed invention "are identified as either essential elements (where substitution of another element or omission takes the device outside the monopoly) or non-essential elements (where substitution or omission is not necessarily fatal to an allegation of infringement)."Footnote 5 In carrying out this identification of essential and non-essential elements, all elements set out in a claim are presumed essential, unless it is established otherwise or is contrary to the language used in the claim.Footnote 6

Subject-Matter

Once the subject-matter defined by a claim has been determined through purposive construction, it is then necessary to determine whether that subject-matter complies with all of the requirements of the Patent Act.Footnote 7 Included in these requirements are that the subject-matter defined by a claim must be patentable subject-matter, meaning (having regard to the definition of "invention" in section 2 of the Patent Act) that it be an art, process, machine, manufacture or composition of matter or an improvement in one of the foregoing and must, in accordance with subsection 27(8) of the Patent Act, not be a mere scientific principle or abstract theorem.Footnote 8

To be both patentable subject-matter and not be prohibited under subsection 27(8) of the Patent Act, the subject-matter defined by a claim must be limited to or narrowerFootnote 9 than an actual inventionFootnote 10 that either has physical existence or manifests a discernible physical effect or changeFootnote 11 and that relates to the manual or productive arts, meaning those arts involving or concerned with applied and industrial sciences as distinguished in particular from the fine arts or works of art that are inventive only in an artistic or aesthetic sense.Footnote 12

For each claim, the identification of the actual invention must be grounded in a purposive construction of the claimFootnote 13 and cannot be determined solely on the basis of a literal reading of the claim, or a determination, not anchored in the language of the claim, of the "substance of the invention" within the meaning of that phrase as used by the Supreme Court of Canada in paragraph 46 of Free World Trust v Électro Santé Inc., 2000 SCC 66.Footnote 14

An actual invention may consist of either a single element that provides a solution to a problem or of a combinationFootnote 15 of elements that cooperate together to provide a solution to a problem. Where an actual invention consists of a combination of elements cooperating together, all of the elements of the combination must be considered as a whole when considering whether there is patentable subject-matter and whether the prohibition under subsection 27(8) of the Patent Act is applicable.Footnote 16

An actual invention that includes a disembodied idea, a scientific principle or an abstract theorem is not patentable unless the disembodied idea, scientific principle or abstract theorem is part of a combination of elements that cooperate together and that combination has physical existence or manifests a discernible physical effect or change and relates to the manual or productive arts.Footnote 17

An element of a claimed invention that is identified as essential for establishing the fences of the monopoly under purposive construction is not necessarily part of the actual invention. For example, an element may be an essential element of a claim only because the applicant intended to limit the scope of the monopoly being claimed to less than what the applicant actually invented. An element may thus be an essential element of the claim because the applicant intended it to be essential even though it has no material effect on the working of the invention.Footnote 18 Such an element would not form part of the actual invention because the fact that it has no material effect on the working of the invention means it does not cooperate with other elements of the claimed invention.

The application of these general principles to specific situations is further elaborated in the ensuing sections.

Computer-implemented inventions

The mere fact that a computer is identified to be an essential element of a claimed invention for the purpose of determining the fences of the monopoly under purposive construction does not necessarily mean that the subject-matter defined by the claim is patentable subject-matter and outside of the prohibition under subsection 27(8) of the Patent Act. In such a case, it is necessary to consider whether the computer cooperates together with other elements of the claimed invention and thus is part of a single actual invention and, if so, whether that actual invention has physical existence or manifests a discernible physical effect or change and relates to the manual or productive arts.

In addition, the fact that a computer is necessary to put a disembodied idea, scientific principle or abstract theorem into practice does not necessarily mean that there is patentable subject-matter even if the computer cooperates together with other elements of the claimed invention. If a computer is merely used in a well-known manner,Footnote 19 the use of the computer will not be sufficient to render the disembodied idea, scientific principle or abstract theorem patentable subject-matter and outside the prohibition under subsection 27(8) of the Patent Act.Footnote 20

In the case of a claim to a computer programmed to run a mathematical algorithm, if the computer merely processes the algorithm in a well-known manner and the processing of the algorithm on the computer does not solve any problem in the functioning of the computer, the computer and the algorithm do not form part of a single actual invention that solves a problem related to the manual or productive arts.  If the algorithm by itself is considered to be the actual invention, the subject-matter defined by the claim is not patentable subject-matter or is prohibited under subsection 27(8) of the Patent Act.

On the other hand, if running the algorithm on the computer improves the functioning of the computer, then the computer and the algorithm would together form a single actual invention that solves a problem related to the manual or productive arts and the subject-matter defined by the claim would be patentable subject-matter and not be prohibited under subsection 27(8) of the Patent Act.

Similarly, a business method that is not itself patentable subject-matter or is prohibited under subsection 27(8) of the Patent Act because it is an abstract idea does not become patentable subject-matter and outside of the subsection 27(8) prohibition merely because it is implemented using a computer. To constitute patentable subject-matter and be outside the subsection 27(8) prohibition, a business method that is an abstract idea must cooperate with other elements of the claimed invention so as to become part of a combination of elements making up an actual invention that relates to the manual or productive arts and that either has physical existence or manifests a discernible physical effect or change.

Medical diagnostic methods

As with any other claim, all elements set out in a medical diagnostic method claim are presumed essential, unless it is established otherwise or is contrary to the language used in the claim.  A claim to a medical diagnostic method often includes an element correlating a specific analyte or the result of a medical test to a disease. A correlation, on its own, would generally be considered an abstract or disembodied idea. In many cases, a claim to a medical diagnostic method further includes one or more physical steps that comprise carrying out a medical test or determining the presence or quantity of the analyte in a sample. Such steps may include, for example, means for identifying, detecting, measuring, etc. the presence or quantity of an analyte.

An abstract idea that is an element of a claim that cooperates with other elements of the claim becomes part of a combination of elements making up a single actual invention. In such cases, all of the elements of the combination are considered as a whole and may constitute patentable subject-matter if the actual invention either has physical existence or manifests a discernible physical effect or change. 

Thus, a diagnostic method claim that defines a combination of elements that cooperate together so as to form a single actual invention that includes physical means for testing or for identifying, detecting, measuring, etc. the presence or quantity of an analyte in a sample would be considered to be patentable subject-matter and not to be prohibited under subsection 27(8) of the Patent Act.Footnote 21

Where a computer is involved in the method, please also refer to the section on Computer-implemented inventions above.

Medical uses

It is well established that methods of medical treatment and surgery are not patentable subject-matter because they do not fall within the manual or productive arts.Footnote 22

As with any other claim, all elements set out in a medical use claim are presumed essential, unless it is established otherwise or is contrary to the language used in the claim. An actual invention of a medical use claim may consist of a combination of all the essential elements of the claim where those elements cooperate together.

An actual invention that has physical existence or manifests a discernible physical effect or change and does not otherwise fall within a jurisprudential exclusion (e.g., methods of medical treatment) would be patentable subject-matter.

Where an actual invention includes one or more essential elements that comprise an active medical treatment step or surgical step or that restrict, prevent, interfere with, or require the exercise of the professional skill and judgment of a medical professional, the actual invention is an excluded method of medical treatment and is not patentable subject-matter.

It is noted that in cases where at least one of the essential elements of the actual invention limits the claimed use to a dosage, a range of potential dosages that a patient may receive, and/or a dosage regimen, regardless of whether these are fixed and/or cover a range, this fact alone is not determinative of whether the claim is patentable subject-matter. It is also necessary to consider whether the exercise of professional skill and judgment of a medical professional is part of the actual invention. For example, professional skill and judgment may be involved if a medical professional is expected to monitor or make adjustments to the treatment, or make a selection of a dosage from a claimed range (i.e., in cases where not all dosages in the range will work for all subjects within the treatment group). In such cases, the subject-matter defined by the claim would encompass a method of medical treatment and would not be patentable subject-matter.

Examples

Examples of Patentable Subject-Matter Analysis