The Guidelines for Examination at the European Patent Office have recently been revised in relation to mathematical methods (EPO GL 2018, G-II, sections 3.3 to 3.3.2). The revisions are aimed at clarifying the circumstances under which claims incorporating a mathematical method could overcome statutory exclusions to patentability under the European Patent Convention (EPC). Specific guidance relating to Artificial Intelligence and Machine Learning, and simulation, design or modelling, has also been introduced.

Mathematical methods are excluded from the definition of an invention under Art. 52(2)(a) EPC, i.e. a claim reciting only a purely abstract mathematical method would not be considered to be an invention by the EPO. However, in accordance with Art. 52(3) EPC, the above exclusion applies only to the extent to which a claim relates to a mathematical method. Therefore, a claim which reciting a mathematical method and also a technical means, such as a computer, is considered to contain subject-matter which has a technical character as a whole, and therefore does not fall under the statutory exclusion under Art. 52(2)(a) EPC. Such a claim can therefore be further assessed to determine if it satisfies the requirements of novelty and inventive step under the EPC.

However, in the assessment of inventive step, only features which are considered to be of a technical character, i.e. to contribute to a technical effect, will be taken into account by the EPO. Therefore if it is considered that a mathematical method within a claim is non-technical in nature, it will be excluded during the EPO’s consideration of inventive step.

In the revisions to the Guidelines, the EPO has clarified that a mathematical method contributes to a technical character if it has a technical purpose, by its application to a field of technology, and/or, if it has been adapted to a specific technical implementation.

Referring to the technical purpose requirement, the Guidelines recite decisions T 1227/05 and T 1358/09, and provide specific examples of technical purposes, including controlling a specific technical system or process, digital audio, image or video enhancement or analysis, speech recognition, encoding/decoding data for reliable and/or efficient transmission or storage, encrypting/decrypting or signing electronic communications, optimising load distribution in a computer network, providing a genotype estimate based on an analysis of DNA samples, providing a medical diagnosis by an automated system processing physiological measurements, or simulating the behaviour of a class of technical items, or specific technical processes, under technically relevant conditions.

The Guidelines state that the purpose must be specific, rather than generic. Furthermore it is not sufficient that the mathematical method may serve a technical purpose; the claim must also be functionally limited to the technical purpose either explicitly or implicitly, for example, by establishing a sufficient causal link between the technical purpose and the mathematical method steps.

To satisfy the requirement of technical implementation, a mathematical method must be particularly adapted for a specific, not generic, technical implementation, i.e. by its design being motivated by technical considerations of the internal function of the computer (T 1358/09).

By way of example, the Guidelines state the adaptation of a polynomial reduction algorithm to exploit word-size shifts matched to the word size of the computer hardware is based on such technical considerations, and can contribute to producing a technical effect of an efficient hardware implementation of said algorithm. Referring specifically to Artificial Intelligence and Machine Learning (EPO GL 2018, G-II, section 3.3.1), specific examples are provided of subject matter which would meet the technical purpose and/or technical implementation requirements: the use of a neural network in a heart-monitoring apparatus for the purpose of identifying irregular heartbeats, and the classification of digital images, videos, audio or speech signals based on low-level features (e.g. edges or pixel attributes for images).

However, classifying text documents solely in respect of their textual content is not per se a technical purpose but a linguistic one (T 1358/09). Furthermore, classifying abstract data records or even "telecommunication network data records" without any indication of a technical use being made of the resulting classification is also not per se a technical purpose, even if the classification algorithm may be considered to have valuable mathematical properties such as robustness (T 1784/06).

The above principles are also applied to simulation, design or modelling (EPO GL 2018, G-II, section 3.3.2). Examples of a technical purpose provided by the Guidelines are the numerical simulation of the performance of an electronic circuit subject to 1/f noise or of a specific industrial chemical process.

Examples provided of a subject matter providing a technical contribution are; a computer implemented method of designing an optical system using a formula for determining technical parameters such as refractive indices and magnification factors for given input, and an iterative computer simulation to determine a maximum value for an operating parameter of a nuclear reactor.

A technical effect cannot be denied solely on the basis that the simulation precedes actual production and/or do not comprise a step of manufacturing a physical end product.

Examples provided of subject-matter which would not be deemed to be contribute to a technical purpose are, a marketing campaign, an administrative scheme for transportation of goods or determining a schedule for agents in a call centre. Furthermore, a generic limitation, e.g. "simulation of a technical system", does not define a relevant technical purpose.

Further examples are provided relating to computer-aided design, citing T 471/05 and T 625/11, following which, the determination of a technical parameter intrinsically linked to the functioning of the technical object, where the determination is based on technical considerations, is considered to be a technical purpose. The Guidelines contrast this against the computer-aided determination of technical parameters which depend on decisions to be taken by a human user, wherein the technical considerations for making such decisions are not included in the claim; a technical effect of improved design cannot be acknowledged since such an effect would not be causally linked to the claim features (T 835/10).

Furthermore, computer-implemented methods which result merely in an abstract model of a product, system or process, are not per se considered to be a technical effect, even if the modelled product, system or process is technical (T 49/99, T 42/09).

Whilst EPO practice relating to mathematical methods has not been substantively changed, the revisions to the Guidelines provide more clarity to the definition of patentable and non-patentable subject matter relating to mathematical methods under the EPC, with additional examples and case law references. The updated EPO Guidelines relating to mathematical methods, including links to the cited cases, can be found here.