UK Patents – Is a Neural Network a Computer Program

The UK court case over Emotional Perception's patent application is set to continue into next year. The UK Supreme Court will consider the case and, we expect, be asked to decide what is a computer program.

Earlier the year, we reported on Emotional Perception's success in the High Court, persuading the Judge that because an artificial neural network, ANN, might be implemented in hardware as well as software, its invention was not a computer program as such. The "as such" matters because both UK and European patent law state that the exclusion from patentability of a computer program "shall exclude the patentability of the subject-matter or activities referred to therein only to the extent to which a UK/European patent application or UK/European patent relates to such subject-matter or activities as such". In other words, you can escape the exclusion if the invention is not a computer program or if it includes a computer program but does more – it extends beyond being a computer program as such.

The High Court Judge additionally decided that even if the artificial neural network was a computer program, the invention did more because it was technical in nature by producing an output that "would not otherwise be selected".

The UK IPO appealed to the Court of Appeal which found in its favour, reversing the High Court judgement.

Emotional Perception's case in the Court of Appeal followed its approach in the High Court.  It sought to distinguish a trained ANN from a computer program because the training of the ANN resulted in a machine that was not, in their opinion, directly linked back to the computer program that implemented the ANN. The Court of Appeal disagreed, commenting:

"The code which human programmers write for conventional computers is written in a form which is sometimes called a high level programming language. That is a form which human programmers can understand and grapple with. However, as the Comptroller submitted, ordinary computers work by running machine code, which is different and hard for humans to understand. The machine code is derived by a computer system (normally what is called a compiler program) under the direction of a human programmer. There is no justification for drawing a distinction in law between instructions created by a computer and those created by a human."

The Court of Appeal also compared its thinking to that of the EPO, highlighting EPO decision T 702/20 Mitsubishi/Sparsely connected neural network where the EPO Board of Appeal applied exactly the same approach to a case about an ANN as it applies to other computer implemented inventions, holding that since "a neural network relates to both programs for computers and to mathematical methods", the question was whether it related only to such subject-matter "as such" or whether there was something more.

The Court of Appeal therefore decided that a trained ANN falls within the exclusion from patentability of a program for a computer as such in s1(2) of the 1977 Act. Lord Justice Birss commented "however it is implemented, the weights (by which I mean weights and biases) of the ANN are a program for a computer and therefore within the purview of the exclusion".

Finally, the Court of appeal disagreed with the High Court on its analysis of technical effect. The Court of Appeal followed the UK IPO, deciding that the supposed technical effect that recommended songs based on both semantic and musical properties was of a subjective and cognitive nature, not a technical one and was directed to excluded subject matter.

Emotional Perception has been given permission to take the matter to the Supreme Court, the UK's highest court, where a final decision will be reached. The timing of this and the questions to be asked of the Supreme Court are not yet known.

Reaction:

The exclusion of "computer program" from patentability has always been an oddity, both in the UK and at the EPO. Unless an invention is directed to actual computer program code/routines, it was unusual to see only this exclusion. Typically, if an invention is otherwise technical enough to avoid the other exclusions such as "mental acts", "schemes, rules and methods of doing business" or "mathematical methods", it would also avoid the computer program exclusion.

Emotional Perception is trying to argue that its ANN is not a computer program and therefore qualifies the invention as being non-excluded without needing other technical effects. This can be contrasted to the IBM cases at the EPO where it was decided that a computer program was technical but would not in itself bring about a technical effect beyond what would be expected from a computer implementation. In other words, something more is needed.

I agree with Lord Justice Birss's decision in the Court of Appeal – weights produced from training an ANN are just as much computer program instructions as the machine code that a compiler or interpreter produces from higher level code (which it incidentally also optimises during compilation and the machine code is also a step away from what the programmer inputted).

It will be interesting to see how the Supreme Court view the issues.

Irrespective of the final decision, it should be noted that inventions in neural networks and other machine learning approaches are patentable in UK and Europe and are not classified as computer programs. However, if the ANN or other machine learning approach is conventional, it cannot be relied upon to distinguish the invention over prior art (and we are back to looking for "something more"). It should also be appreciated that patent examiners are also becoming much more aware of sufficiency issues surrounding neural networks – often a neural network or other machine learning approach can only be reproduced if the training data, cost functions and architecture are explained in detail. This is a complex area, but one in which we have legal and technical expertise.  Please contact us for advice and guidance on this area.