Emotional Perception AI Ltd v Comptroller in the Supreme Court

Supreme Court of the United Kingdom

Author Kelsey Farish Licence CC BY 4,0  Source Wikimedia Commons

 

Jane Lambert

Supreme Court (Lord Briggs, Lord Hamblen, Lord Leggatt, Lord Stephens, and Lord Kitchin) Emotional Perception AI Ltd. v Comptroller General of Patents, Designs and Trade Marks [2026] UKSC 3

This was an appeal by Emotional Appeal AI Limited ("the applicant") against the Court of Appeal's decision in Emotional Perception AI Ltd v Comptroller-General of Patents, Designs and Trade Marks [2024] Bus LR 14, [2023] WLR(D) 500, [2023] EWHC 2948 (Ch) (21 Nov 2023) to uphold the examiner's objection to the patentability of the applicant's invention. I discussed the Court of Appeal's reasoning in Patents - the Appeal in Comptroller v Emotional Perceptions on 26 Aug 2024.

The Invention

The applicant applied to the United Kingdom Intellectual Property Office for a patent for a method of training a neural network to reflect emotional perception and related system and method for categorizing and finding associated content under application number GB1904713.3.  It was a system or method that used an artificial neural network ("ANN") to replicate similarities and differences that a human being might subjectively perceive between different files of information by reference entirely to objectively measurable physical properties of those files. Those files could be video, audio, images or text. The commercial purpose of the invention was to enable a person interested in a particular type of file to obtain the recommendation of another file calculated to elicit a similar emotional response.

ANN   

An ANN is a network of artificial neurons, loosely akin to the neurons in a human brain. These "neurons" are nodes arranged in layers.  Each neuron and layer is connected to others. Data presented to the first layer of neurons (known as the "input layer") is processed through each layer in turn until the final layer of the network ("the output layer) generates an output. The neurons in a layer below the input layer will each receive inputs from one or more neurons in the layer above. Each input value to a neuron is assigned a separate weight. The weighted input values are aggregated together and adjusted with a bias. A mathematical function (known as an "activation function") is applied to the aggregated value to generate the neuron's output value. That value is then transmitted as an input to each connected neuron in the next layer.  An ANN can be implemented on a conventional digital computer or on a dedicated piece of hardware that has a particular network architecture embedded in it.

An important feature of an ANN is that it can be trained to perform a task and to improve the quality of its performance by an iterative process of adjustment. The training process typically involves repeatedly inputting a set of data for which desired (or target) outputs have been independently identified. On each iteration, the output generated by the ANN is compared with the target output using a "loss function" to measure the difference (or degree of error) between the actual output and the target output. That information is then used to adjust the variable parameters of the network (the weights and biases) to reduce the likelihood of future error. A commonly used technique is called backpropagation. In essence, this involves calculating how much each weight and bias contributed to the total error and adjusting the weights and biases accordingly.

Once the performance of the ANN is perceived to have been optimized by the training process, the ANN is ready to use for its intended task. At this stage, the weights and biases are frozen, so that they are static and no longer subject to adjustment. New data can then be presented to the ANN, which will process the data and generate an output applying the weights and biases arrived at through training.

Prosecution History

The examiner objected to the patent application on the ground that it was a program for a computer as such which was excluded from patentability by s.1 (2) (c) of the Patents Act 1977.  As the objection could not be resolved, the applicant appealed to the Comptroller General of Patents, Designs and Trade Marks ("the Comptroller").  The appeal was heard on behalf of the Comptroller by Mr. Phil Thorpe.  In Re Emotional Perception AI Limited's Application BL/O/542/22 of 22 June 2022, he upheld the examiner's objection.  

The applicant appealed to the Patents Court.  Sir Anthony Mann, sitting as a judge of the High Court, allowed the appeal in Emotional Perception AI Ltd v Comptroller-General of Patents, Designs and Trade Marks  [2023] WLR(D) 500, [2024] Bus LR 14, [2023] EWHC 2948 (Ch).  The Comptroller appealed to the Court of Appeal, which restored the decision of the hearing officer in Comptroller General of Patents, Designs and Trade Marks v Emotional Perception AI Ltd  [2024] EWCA Civ 825, [2024] Bus LR 1589, [2024] WLR(D) 339.  

 The Aerotel Guidelines

The Court of Appeal arrived at its decision by applying guidance on the application of s.1 (2) (c) of the Patents Act 1977 that it had laid down in the conjoined appeals of Aerotel Ltd. v Telco Holdings Ltd and others Rev 1 and Macrossan v The Comptroller General of Patents, Designs and Trade Marks  [2007] BusLR 634, [2007] Bus LR 634, [2006] Info TLR 215, [2007] 1 All ER 225, [2007] RPC 7, [2006] EWCA Civ 1371.  It required a patent examiner to apply the following four-step test to determine the patentability of a software-implemented invention:

"(1) Properly construe the claim.
(2) Identify the actual contribution (although at the application stage this might have to be the alleged contribution).
(3) Ask whether it falls solely within the excluded matter.
(4) If the third step has not covered it, check whether the actual or alleged contribution is actually technical."

One of the issues in the appeal to the Supreme Court was whether the Aerotel guidance should continue to be followed.  The others were whether an ANN is or contains a program for a computer and whether the entire subject matter of the claims of the patent application should be excluded?

The Hearing

The appeal came on before Lord Briggs, Lord Hamblen, Lord Leggatt, Lord Stephens and Lord Kitchin on 21 and 22 July 2025.  The proceedings were recorded and can be viewed on the Supreme Court's web page for this case.   Judgment was handed down in Emotional Perception AI Ltd v Comptroller General of Patents, Designs and Trade Marks [2026] UKSC 3 on 11 Feb 2026.   A summary of the Court's judgment, which can also be viewed on the same web page, was delivered by Lord Briggs on 11 Feb 2026.   The full judgment was written by Lord Briggs and Lord Leggatt, but all the other Supreme Court Justices agreed with it.

Issue 1: Should the Aerotel/Macrossan Guidelines be followed?

The Supreme Court decided at para [20] of its judgment that the Aerotel/Macrossan approach should no longer be followed. The Justices noted that the Enlarged Board of Appeal of the Europeam Patent Office had approved in G1/19 Bentley Systems (UK) Ltd/Pedestrian Simulation (Decision G1/19) [2021] EPOR 30) cases that stated that the Aerotel/Macrossan approach was not a good faith implementation of art 52 of the European Patent Convention which s.1 (2) (c) of the Patents Act 1977 is supposed to implement in the United Kingdom. One of those cases held that the Aerotel/Macrossan approach was incompatible with art 52 because that approach had been based on a misunderstanding of the word "invention" as used in the Convention.

At para [31], their lordships agreed that it was now necessary to spell out the approach to the interpretation and application of art 52 (2) that the Board had approved in G1/19.  It was common ground that the Board had approved an "any hardware" approach, which meant that if the subject matter of a claim involved the use of any hardware, art 52(2) was at least prima facie inapplicable.  In T641/00 Comvik GSM AB (Decision T 641/00) 

[2004] EPOR 10, the Technical Board of Appeal considered how the "problem and solution method" should be applied to claims that included both technical and non-technical features.  The  Board's decision was summarized in the report's headnote 

as follows:

"1. An invention consisting of a mixture of technical and non-technical features and having technical character as a whole is to be assessed with respect to the requirement of inventive step by taking account of all those features which contribute to said technical character whereas features making no such contribution cannot support the presence of inventive step.

2. Although the technical problem to be solved should not be formulated to contain pointers to the solution or partially anticipate it, merely because some feature appears in the claim does not automatically exclude it from appearing in the formulation of the problem. In particular where the claim refers to an aim to be achieved in a non-technical field, this aim may legitimately appear in the formulation of the problem as part of the framework of the technical problem that is to be solved, in particular as a constraint that has to be met."

The Supreme Court explained at para [33] of its judgment that the context of this holding was that the Board of Appeal had recognized that the general principles reflected in the Convention required patents to be available for inventions "in all fields of technology" and that "technical character was a sine qua non for an invention.  However, the Technical Board had also acknowledged in para [4] of its decision in T641/00 that an inevitable consequence of the "any hardware" approach is that claims can qualify as an invention even if they contain predominantly non-technical features.   

In T 154/04 Duns Licensing Associates [2004] EPOR 10, the Technical Board of Appeal criticized Lord Justice Jacob's "technical effect approach" as "not consistent with a good-faith interpretation of the European Patent Convention in accordance with Article 31 of the Vienna Convention on the Law of Treaties of 1969" at para [12] of the reasons for its decision.  It added that any reference to the prior art in the context of art 52 (2) would lead to insurmountable difficulties and could not have been intended by the contracting parties. It followed that both the "contribution" and "technical effect" approaches which involved such reference should be abandoned.

Although the Enlarged Board did not expressly criticize the Aerotel/Macrossan approach in G1/19, the Supreme Court held that it must have done so by implication because the Board endorsed the following principles from the Technical Board's decision in Duns Licensing:

"(A) Article 52 (1) EPC sets out four requirements to be fulfilled by a patentable invention: there must be an invention, and if there is an invention, it must satisfy the requirements of novelty, inventive step, and industrial applicability.
(B) Having technical character is an implicit requisite of an 'invention' within the meaning of Article 52 (1) EPC (requirement of 'technicality').
(C) Article 52 (2) EPC does not exclude from patentability any subject matter or activity having technical character, even if it is related to the items listed in this provision since these items are only excluded 'as such' (Article 52 (3) EPC).
(D) The four requirements - invention, novelty, inventive step, and susceptibility of industrial application - are essentially separate and independent criteria of patentability, which give rise to concurrent objections. Novelty, in particular, is not a requisite of an invention within the meaning of Article 52 (1) EPC, but a separate requirement of patentability.
(E) For examining patentability of an invention in respect of a claim, the claim must be construed to determine the technical features of the invention, i.e. the features which contribute to the technical character of the invention.
(F) It is legitimate to have a mix of technical and 'non-technical' features appearing in a claim, in which the non-technical features may even form a dominating part of the claimed subject matter. Novelty and inventive step, however, can be based only on technical features, which thus have to be clearly defined in the claim. Non-technical features, to the extent that they do not interact with the technical subject matter of the claim for solving a technical problem, i.e. non-technical features 'as such', do not provide a technical contribution to the prior art and are thus ignored in assessing novelty and inventive step.
(G) For the purpose of the problem-and-solution approach, the problem must be a technical problem which the skilled person in the particular technical field might be asked to solve at the relevant priority date. The technical problem may be formulated using an aim to be achieved in a non-technical field, and which is thus not part of the technical contribution provided by the invention to the prior art. This may be done in particular to define a constraint that has to be met (even if the aim stems from an a posteriori knowledge of the invention)."

The Enlarged Board made the following additional comments on principle (F) and how the technical and "non-technical" features can interact at paras [32] to [33] of its decision in G1/19:

"[32]. In this context, the term 'non-technical features' refers to features which, on their own, would be considered 'non-inventions' under Article 52(2) EPC. Whether such features contribute to the technical character of the invention has to be assessed in the context of the invention as a whole.
[33] The same manner of assessment applies to features which can be considered to be technical per se: they do not necessarily contribute to the technical solution of a technical problem. An invention may have (i) technical features which contribute, (ii) technical features which do not contribute, (iii) non-technical features which contribute and (iv) non-technical features which do not contribute to the technical solution of a technical problem and thereby potentially to the presence or not of an inventive step. While (i) and (iv) are self-evident, features according to (iii) have been established by the case law described above (principle (F): non-technical features interacting with the technical subject matter of the claim for solving a technical problem). Case (ii) occurs if features that per se qualify as technical cannot contribute to inventive activity because they have no technical function within the context of the claimed invention. Even before the Comvik approach was established, technically non-functional modifications (even if they could per se be considered technical) could be considered irrelevant in the assessment of inventive step." (citations omitted).

The Board commented as follows on the "two hurdle approach" which the Justices in Emotional Perception AI considered to be of particular relevance to the appeal in front of them:

"[37] To be patentable, any invention has to pass the eligibility test under Article 52 EPC (i.e. it must not fall under the “non-inventions” mentioned there) and also fulfil the other criteria listed in that article (novelty, inventive step, etc.). For computer-implemented inventions, the twofold test for patent eligibility and for inventive step (using the COMVIK criteria) is often referred to as the 'two-hurdle approach' ......

[38] It may be that a shift has taken place in the relative level of each of these two hurdles in the sense that it has become easier to clear the eligibility hurdle of Article 52 EPC (see point B.II.a above) and more difficult to pass the inventive step hurdle (see point B.II.b above) of Article 56 EPC. As [a] result of this shift, it could be said that there is now in effect an additional intermediate step to assess the 'eligibility of the feature to contribute to inventive step.'

[39]  The two-hurdle approach for computer-implemented inventions actually entails three steps. Establishing whether a feature contributes to the technical character of the invention constitutes an intermediate step between assessing (i) the invention’s eligibility under Article 52 EPC, and (ii) whether the invention is based on an inventive step vis-àvis the closest prior art. This additional intermediate step serves as a filter for features contributing to a technical solution of a technical problem in view of the closest prior art. Only those distinguishing features can contribute to [an] inventive step."

Although the decisions of the Boards of Appeal are not strictly binding, the courts of the United Kingdom respect them because national courts of all contracting parties are expected to seek a uniform interpretation of the Convention, and of the domestic legislation that implements it. The Supreme Court considered the Comptroller's arguments for adhering to the Aerotel/Macrossan approach between paras [50] and [55] of its judgment but decided to depart from it because that approach had been emphatically rejected as a means of applying arti 52 (2) and (3) by the Enlarged Board in G1/19.  The Justices amplified their reasons for not following Aerotel/Macrossan between [56] and [64] of their judgment.

That raised the question: "what method, approach or guidance should this court provide by way of replacement?" In the justices' view,

".... the approach which should be adopted by courts in the UK is that contained in the Duns principles other than principle G (and the second paragraph of the Comvik headnote), as explained by the further reasoning in G1/19, in particular about the need for an intermediate step between 'any hardware' and inventive step to determine which features in a "mixed" invention contribute to its technical character:."

Such an approach continues to recognise the validity of the Pozzoli method for identifying an inventive step.

Issue 2: Is an ANN (or does it contain) a "Program for a Computer"

The applicant submitted that it was wrong to regard a physical ANN as a computer at all, as it has no CPU capable of receiving, interpreting and executing instructions that constitute a "program for a computer". It also has no "program" in the sense of a sequence of logical instructions, each commanding the CPU to execute a specific logical function. It submitted that as a hardware ANN neither is nor contains a program for a computer, the same must apply to an "emulated ANN", that is to say, an ANN on a digital computer as it is functionally the same as a physical ANN and operates in the same manner.

The Comptroller argued that an ANN in any form in which it is implemented is a programmable computer and has a program.  It consists of a set of adjustable parameters that instruct the machine to perform a specific task. Those adjustable parameters are the weights and biases of the ANN. They are a program that makes the trained ANN perform the task for which it has been programmed through the process of training.

The Court of Appeal accepted the Comptroller's analysis. The Lord Justices defined a computer as "a machine which processes information" and a computer program as "a set of instructions for a computer to do something": more specifically, a set of instructions which causes the machine to process information in a particular way. They characterised an ANN as "a machine which processes information" and therefore a computer.  They identified the weights and biases of an ANN as a computer program.

In the Supreme Court, the applicant took issue with the Court of Appeal's definition and maintained its case that the term "computer" should be construed more narrowly to mean a device with a CPU, which can manipulate data by receiving and executing a sequence of logical instructions. A "program for a computer" is such a sequence of logical instructions. Applying those definitions, an ANN is not a computer, in particular because it has no CPU and there is no program for a computer within an ANN, even when it is implemented on a computer of a conventional kind, because there is no series of instructions stored or executed anywhere in the system, and no coded command instructing any part of the computer to execute any particular logical function.

The Justices agreed that the description of a computer as "a machine which processes information" was too broad, in that it encompasses many devices which are not generally considered to be computers.  These would include a basic oven, a smoke detector, an analogue radio or record player with a volume control, and an old-fashioned jukebox that plays a song selected by a user. Each of those devices receives and processes information to generate an output. The only difference between them and a digital computer is that they are not used to perform computations. On the other hand, their lordships saw no reason to confine the term "computer" to conventional digital computers of the kind described by the applicant or the concept of a "program for a computer" to a set of instructions addressed to a conventional digital computer.  They concluded that Mr. Thorpe had been right to hold that an ANN was a program for a computer. It followed that the exclusion from patentability for "programs for computers" provided by article 52 (2) (c) of the EPC was engaged in this case.

Issue 3: Is the Entire Subject Matter of the Claims excluded?

The Supreme Court's conclusion on issue 2 made it necessary to consider whether the entire subject matter of the applicant's claims fell within the scope of the exclusion of "programs for computers ... as such" or whether it included technical features and so qualified as an "invention" within the meaning of article 52 (1). The question had been addressed by the hearing officer and the courts below by applying the Aerotel/Macrossan approach.  Having rejected that approach and applying the "any hardware" approach, it followed that the claims were to an "invention" and therefore not excluded by art 52 (2) (c).  

Although the claimed method involved an ANN which is a program for a computer, it also involved technical means because the ANN can only be implemented on some form of computer hardware. In addition, the claims refer to a database for storing data files, a communications network and a user device, all of which require or constitute hardware. That was sufficient to show that the subject matter of the claims had technical character and was not a computer program "as such". It follows that the IPO had been wrong to decide, for the reason that it did, that the application for a patent should be refused.

Further Help

As Lord Briggs and Lord Leggatt noted at para [99] of the judgment, it would have been possible to stop at this point and simply decide that the case should be sent back to the IPO to consider whether the invention satisfies the requirements of novelty and inventive step. No assessment had been made or view expressed by the IPO in relation to those matters, but their lordships were apprehensive that to say nothing more about the merits would be unhelpful and might result in considerable further cost and delay. They recognized that it was in the interests of the IPO and of patent applicants generally that they should try to give such further help as they properly could regarding how applications for computer-implemented inventions should be approached once they had cleared the first, very low hurdle of satisfying the "invention" test through the use of "any hardware". As will appear, that further assistance was limited by the way in which the matter had reached the Supreme Court.

The Intermediate Step

One issue on which the Court offered its assistance was to explain the meaning of the so-called "intermediate step" lying between steps (1) and (2) of "the two-hurdle approach" for computer-implemented inventions mentioned in paras [37] to [39] of the Enlarged Board's reasons for its decision in G1/19.   I touched upon those issues in my discussion of those paragraphs. The Justices set out their guidance on the issue between paras [104] and [111] of their judgment in Emotional Perception AI.

Application to this Case

Their lordships considered whether they should define further the "intermediate step" for the purposes of its implementation by the IPO or UK courts in cases involving programs for computers or to carry it out in relation to the claims in this case. They saw formidable difficulties in either course.   All the arguments they had heard had been based on the assumption that Aerotel/Macrossan was still good law.  They had rejected that course and had ruled that the approach to be followed was the one set out by the Enlarged Board in G1/19, adopting all but the last of the Duns principles. 

Even on that different approach to the interpretation and application of art 52, the claims comprised a program for a computer as the Court of Appeal had held.  The claimed invention was not a program for a computer "as such" within the meaning of art 52 (2) and (3). Contrary to the decision of the hearing officer and the judgment of the Court of Appeal, the claims did not fall foul of art 52, and the subject matter was an invention.   Accordingly, under the Convention those claims qualified for assessment under the headings of novelty, inventive step and industrial application.

The Justices heard argument about whether replacing the Aerotel/Macrossan approach with that set out in G1/19 would require a departure from the approach to inventive step outlined in Pozzoli because of the supposed need to incorporate the EPO's problem and solution approach to determining whether there had been an inventive step. They decided not to discuss that point because the appealwas about Aerotel/Macrossan. 

They did not hear argument on how the "intermediate step" was to be applied to computer-implemented inventions.   Nor did they hear argument or on whether or in what way English cases that had considered whether a computer-implemented invention had a relevant technical effect might continue to provide assistance when applying the approach set out in G1/19.

There are rare occasions when a new question arises for the first time in the Supreme Court but is not addressed in the parties' written cases can be tackled with the help of further written submissions and even a further hearing, but this case was not one of them. This appeal raised issues of fundamental importance for the UK's application of the EPC to computer-implemented claims, particularly in the rapidly expanding field of AI. It would be unwise for the Court to embark on carrying out the analysis required by the intermediate step and in doing so to create binding precedent without the benefit of both in-depth legal argument and the views of the IPO and the specialist judges in the lower courts, none of which were available to their lordships.

Disposal

They concluded that the right course was to allow the appeal, set aside the decision of the hearing officer from which the appeal originated, and confine the Court's ruling to the matters resolved above, including those aspects of the "intermediate step" which they had discussed. How it applies to this invention, and whether the features of the invention which contribute to its technical character can be considered to involve an inventive step, were questions to be considered by Mr Thorpe.

Comment

This was a momentous decision that reverses nearly 20 years of decisions by judges, hearing officers and patent examiners.  Many cases, including at least one in which I have been briefed, would have been decided differently under the G1/19 and paragraphs (A) to (F) of the Duns principles.   The Supreme Court's judgment is likely to affect patents for inventions other than those for the application of artificial intelligence and software implementation.  As Lord Briggs and Lord Leggatt acknowledged, this judgment could well have a bearing on the Windsurfing/Pozzoli test for obviousness.

Anyone wishing to discuss this appeal is welcome to call me on +44 (0)20 7404 5252 during normal office hours or send me a message through my contact page at any time.