On 7 January 2019, the United States Patent and Trademark Office (“USPTO”) published two guidance notes on its practice for examining subject matter eligibility and clarity of claims for computer implemented inventions. In this article, we compare the USPTO’s new guidance with the established practice of the European Patent Office (“EPO”), and provide practical suggestions for drafting patent applications that will satisfy the requirements of both patent offices.

Subject Matter Eligibility

The EPO has a long-established and consistent practice for examining the patentability of computer-implemented inventions, which is based on a body of case law that has evolved gradually over many decades. In contrast, the USPTO’s practice for examining subject matter eligibility under 35 U.S.C. § 101 has been less consistent, and has seen particular upheaval following the decision of the U.S. Supreme Court in Alice Corporation Pty. Ltd. v. CLS Bank International in 2014.

In order to improve the consistency and predictability of the USPTO’s application of § 101, the new guidance on subject matter eligibility identifies the following three “groupings” of patent ineligible “abstract ideas”:

  1. Mathematical concepts – mathematical relationships, mathematical formulas or equations, mathematical calculations;
  2. Certain methods of organizing human activity – fundamental economic principles or practices (including hedging, insurance, mitigating risk); commercial or legal interactions (including agreements in the form of contracts; legal obligations; advertising, marketing or sales activities or behaviors; business relations); managing personal behavior or relationships or interactions between people (including social activities, teaching, and following rules or instructions); and
  3. Mental processes – concepts performed in the human mind (including an observation, evaluation, judgment, opinion).

The USPTO’s new “groupings” closely correspond to some of the exclusions from patentability that have existed in Europe for over forty years. For example, the “mathematical concepts” and “mental processes” groupings identified by the USPTO are similar to the exclusions on “mathematical methods” and “methods for performing mental acts” that are set out in Article 52(2)(a) and (c) EPC. Although the “certain methods of organizing human activity” grouping does not at first glance correspond to one of the European exclusions, the USPTO’s examples of such methods all relate to subject matter that would be excluded from patentability In Europe as being a “method for doing business” under Article 52(2)(c) EPC.

We anticipate that the USPTO’s guidance on subject matter eligibility will lead to a greater divergence between USPTO and EPO practice. In view of the previously-mentioned similarities between the USPTO’s new “groupings” and the existing exclusions in Europe, most inventions that are found to be unpatentable by the USPTO will continue to be unpatentable in Europe. However, there are likely to be areas of technology that are unpatentable in accordance with the EPO’s established practice, but which fall outside the USPTO’s groupings. For example, graphical user interfaces (GUIs) are difficult to patent at the EPO, but seem not to be covered by the USPTO’s groupings. For those areas of technology, we expect the USPTO to adopt a more permissive approach than the EPO, thus increasing the divergence of the two offices’ practices.

Claims for a “Practical Application of a Judicial Exception”

An interesting aspect of the guidance on subject matter eligibility is the creation of a new safe harbour for claims directed to a “practical application of a judicial exception”.

In Step 2A of the USPTO’s test for assessing subject matter eligibility, it is necessary to ask whether a claim is “directed to a judicial exception”, such as a law of nature, a natural phenomenon or an abstract idea. The claim is patent eligible if it is found not to be directed to a judicial exception. Conversely, further analysis of the claim is needed if it is found to be directed to a judicial exception, with the possibility that the claim will be deemed patent ineligible.

In accordance with the guidance on subject matter eligibility, a claim is judged not to be directed to a judicial exception if the claim recites a practical application of that judicial exception. The claim is thus found to be patent eligible.

The USPTO’s guidance mirrors recent changes to the EPO’s practice for examining mathematical methods, as set out in the November 2018 edition of the Guidelines for Examination in the EPO (Chapter G-II, 3.3). Under the EPO’s new practice, a mathematical method can contribute to the technical character of an invention if the claim is limited to a specific “technical application” of the mathematical method. In this case, the mathematical method is capable of distinguishing over the prior art when inventive step is examined by the EPO.

When drafting patent applications for inventions on the borderline of patent eligibility, we suggest that any technical use cases of the invention are described and claimed. For example, if the invention could conceivably be used to control a specific technical system (such as an industrial process, or a device other than a general purpose computer), measure a physical property, or optimise the communication or storage of data, then this should be disclosed. Drafting the application in this manner will provide a possibility of overcoming a § 101 rejection in the U.S., or an inventive step objection in Europe, by limiting the claims to a specific use case of the invention.

Functional Claim Language

It is common for claims for computer-implemented inventions to include functional language, such as “means for performing X”.

In Europe, the use of functional language is often the simplest way to draft claims that cover all of the many ways in which some inventions can be implemented in software. The use of functional claim language is permitted by the Guidelines for Examination in the EPO (Chapter F-IV, 3.9.1), which notes that there is no particular preference among the different types of wording that are commonly seen in practice (e.g. “means for”, “adapted to”, “configured to”, etc.).

However, it has long been the case that functional claim language is problematic in the US. Under 35 U.S.C. § 112(f), a claim that recites a “means” or “step” for performing a function, but without reciting the structure that performs that function, is construed to cover the structure that is described in the specification (and any equivalents thereof). Thus, whereas functional claim language typically has a broad scope in Europe, it can have a much a narrower scope in the U.S.

The USPTO’s guidance on clarity provides helpful suggestions on functional terms that should be avoided when drafting claims. In addition to avoiding the words “means” and “step” that are mentioned in § 112(f) itself, other terms to avoid include:

mechanism for”, “module for”, “device for”, “unit for”, “component for”, “element for”, “member for”, “apparatus for”, “machine for” and “system for”.

However, the guidance points out that there is no fixed list of terms that will always result in a claim being interpreted in accordance with § 112(f), nor is there a fixed list of terms that will always avoid such interpretation.

When drafting claims, we suggest that functional language is used with care. Where appropriate, one should consider using terminology that implies a structural limitation. For example, the claim term “means for calculating” could alternatively be expressed as “a processor configured to calculate”. The latter wording is broad, yet should be acceptable in both the U.S. and Europe. To keep open the option to use broader functional language in Europe, the “Summary” section of the description could include additional statements of invention that use “means for” language.

Content of the Disclosure

The guidance on clarity also emphasises the importance of ensuring that a patent specification contains a complete disclosure of the invention.

In Europe, it is necessary for the patent specification to disclose the invention in a manner sufficiently clear and complete for it to be carried out by a person skilled in the art (Articles 83 and 100(b) EPC). Failure to comply with this requirement is a ground for refusing an application or revoking a patent. In practice, however, it is rare for the EPO to invoke this ground when refusing applications, or revoking patents, for computer-implemented inventions.

Whereas the EPO’s approach to examination places very few requirements on the draftsperson, the USPTO’s guidance on clarity is a reminder that, when drafting a patent application for a computer-implemented invention that will be filed in the U.S., the specification should disclose an algorithm for performing the claimed functionality. In this regard, the guidance defines an algorithm as “a finite sequence of steps for solving a logical or mathematical problem or performing a task”. The algorithm may be expressed as a mathematical formula, as prose, as a flow chart, or in any other suitable manner. Care should be taken to ensure that the disclosed algorithm is sufficient to perform all of the functionality that is claimed. Failure to disclose an algorithm can result in claims of the U.S. patent or application being found to be indefinite under 35 U.S.C. § 112(b) and lacking written description under 35 U.S.C. § 112(a).

In general, we suggest providing the necessary disclosure of the algorithm through a combination of a flow chart (in the drawings) and a detailed written description of each step of the flow chart. At the very least, the flow chart should include a step corresponding to each step of the independent method claim(s). The flow chart should ideally also include a step corresponding to each step of the dependent method claims but, to allow more flexibility for amendment at the EPO, the description should make clear which steps are optional.