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Halliburton Energy Services v Comptroller [2011] EWHC 2508: UK Patents Court decides (again) between UK and EPO approaches to patentable subject-matter issues.

My thanks to Paul Cole and Paul Casbon from Lucas & Co., Warlingham, UK, UK and European patent attorneys, for this guest post on a recent UK Patents Court decision on patentable subject matter:

Although arising mainly under the “mental act” exclusion contained in the UK Patents Act, 1977 and in the EPC, an opinion of Colin Birss Q.C. sitting as a judge of the Patents Court and handed down on 5th October 2011 deals with the general approach to be adopted by the UK courts to computer-related inventions and is likely to be highly influential. The decision will also cause the UK IPO to change its current Practice Notice on the patentability of computer programs.

The disputed inventions

The appeal concerned a number of UK patent applications relating to the design of roller cone drill bits for use in oil drilling (Fig. 1). The drill bits were to be formed with cutting elements and cutting structures having cutting element profile angles selected to minimize cone wobble and improve life of associated bearings and seals. The claimed subject matter concerned a computerised design stage for the drill bit involving calculating a three-dimensional mesh for each portion of the earth formation used in the simulated drilling, simulating interaction of each cutting element with each portion of the earth formation for a selected drilling time interval, determining contacts between each mesh segment of each cutting element and mesh segments of the earth formation during the selected drilling time interval, calculating forces acting upon each mesh segment of each cutting element during the selected drilling time interval and outputting to a resource the results of the method.

It was common ground that the application contained patentable subject matter, but the objection raised by the IP Office related to the form of the claim which was considered to relate to an unpatentable mental act.

If they wished to overcome the objection and obtain easy patent grant, Halliburton had only to play the “get out of jail card” of adding the step of manufacturing a drill bit using the results of the method. However they were unwilling to do this because the proposed claim would not give them realistic commercial protection, and the reasons though not stated in the decision are not difficult to discern.

Suppose that a novel drill bit was designed in the UK according to the patented method (including a manufacturing step), and the resulting design data was then sent to China (where there is a corresponding patent application CN 1782321). There would be no direct infringement of the UK patent because the manufacturing step would be carried out in China, not the UK. There would be no contributory infringement by the supply of the design data because on the assumption that the data amounted to an essential element of the invention within s.60(2) of the Patents Act, 1977, it was not intended to put the invention into effect in the UK as required by that sub-section. Nor would there be clear infringement of the Chinese patent if granted because only the manufacturing step would be carried out in China, and the fact that relevant data had been supplied from the UK might well not suffice. In order to obtain a claim worded in a way that had a realistic prospect of being infringed, Halliburton had no alternative but to pursue their claim to the design aspects of the method only.

The meaning of the claim – if your claim uses a computer, say so!

A preliminary dispute was whether the claim covered only simulations carried out on a computer or whether it covered the same steps carried out by a human using paper and pencil. As the claim did not include the word “computer” the IP Office took the position that the crucial simulation steps could be carried out by a person without a computer at all. The Court held that the phrase “ outputting to a resource” would be understood as being to a computer resource such as a memory or printer, and that the claimed subject matter was a computer-implemented method. It commented, however:

“This case is by no means unique as an example of a computer implemented invention in which the word “computer” is conspicuous by its absence from the patent claims.  I am quite certain that one reason for this is a desire by applicants to try and play down the fact that their inventions are really based almost entirely on computer software.  It fools no-one and in some cases makes things more complicated than they need to be.”

Established UK approach or EPO approach?

UK courts and the UK IP Office follow an approach set out by the Court of Appeal in Aerotel v Telco / Macrossan’s Application [2007] RPC 7 and Symbian v Comptroller [2009] RPC 1. The issue of patentability is dealt with under the heading of qualifying subject-matter and the question is decided by considering what task it is that the program (or the programmed computer) actually performs.  A computer programmed to perform a task that makes a contribution to the art which is technical in nature, is a patentable invention and may be claimed as such, as may the program itself. However, if the task the system performs itself falls within the excluded matter and there is no more to it, then the invention is not patentable, examples being computers programmed to operate a method of doing business, such as a securities trading system or a method of setting up a company. In contrast, the EPO adopts an “any hardware” approach in which the issue of patentable subject matter is avoided by anything which can be said to be of a technical nature, but non-technical features are precluded from consideration in relation to inventive step, that approach being set out in Pension Benefit (T931/95), Hitachi (T2587/03) and Microsoft/data transfer (T424/03). It was argued for Halliburton that the Enlarged Appeal Board decision in G3/08 President’s Reference showed that the EPO approach was now settled and that it should therefore be followed by the UK courts.

Judge Birss was of the opinion that UK courts should refuse to make that change. There was no reason why different outcomes should emerge from a consistent application of the approach based on the consistent jurisprudence of the UK (and earlier in the EPO) and the current approach in the EPO. In the Pension Benefit case the concern was not with the result which UK courts recognised as correct but with the reasoning which lead there. In the present case the applicants had submitted that the Examiner had found that the claim was not obvious and so the only hurdle left was the problem of patentability.   They urged the court to take the EPO’s approach to patentability but sought to take advantage of the UK IPO’s approach to inventive step, which would not do.  The EPO’s approach to patentability went hand-in-hand with its special approach to inventive step. It was far from clear that the EPO’s approach when applied as a whole and correctly was any more favourable to patentees than the UK approach.

Attitudes of the UK IPO and the EPO

A further issue which Halliburton raised was the difference in attitude between the two patent offices concerning the treatment of computer-implemented inventions. Judge Birss held that this was not relevant and concluded:

“However, self-evidently the law is not concerned with the attitude of either Office.  The difficulties perceived in the UK with the way the EPO now approaches computer implemented inventions are genuine jurisprudential concerns of respectful nature. As a matter of law computer implemented inventions are just as patentable in the UK as in the EPO.  The Patents Act is in accordance with the EPC in that both contain an exclusion for computer programs as such.  That is a matter of legislation and in my judgment it is not for any court to interpret that exclusion out of existence.”

Mental act – a broad or narrow exclusion?

The court was asked to decide between two possible interpretations of this exclusion. A wide construction was that a method was “a scheme, rule or method for performing a mental act” if it was capable of being performed mentally regardless of whether, as claimed, it was in fact performed mentally.   Read this way a claim to a computer programmed to carry out a method of performing a calculation (say a square root) would not only be caught by the computer program and mathematical method exclusions but would also be covered by the mental act exclusion because calculations are the kind of thing that can be performed by the human mind. A narrow construction was that the exclusion only excluded acts carried out by the human mind, so that a claim to a calculation carried out on a computer could never be caught by the mental act exclusion. The fact that calculations in general were the kinds of thing which were capable of being performed as mental acts was irrelevant.

Judge Birss concluded that the balance of authority in England was in favour of the narrow approach to the mental act exclusion.  Its purpose was to make sure that patent claims cannot be performed by purely mental means and that was all.  The exclusion would not apply if there were appropriate non-mental limitations in the claim.

The outcome on the particular facts

Once the scope of the mental act exclusion had been identified the decision on the particular facts was straightforward. Although obviously some mathematics was involved, the contribution was  not solely a mathematical method (on top of being a computer program) because the data on which the mathematics was performed has been specified in the claim in such a way as to represent something concrete (a drill bit design etc.). Designing drill bits was obviously a highly technical process, capable of being applied industrially. Moreover the detailed way in which this method works – the use of finite element analysis  – was also highly technical. Accordingly the appeal would be allowed and the applications would be remitted to the Comptroller for further prosecution.


The present decision is not the last word on UK/EPO approaches to computer-related inventions because the possibility of another computer-related invention being further appealed to the Court of Appeal remains open. Judge Birss has provided credible reasons for maintaining the approach presently adopted by the UK courts, and his decision does not seem easy to reverse.

However, the differences in attitude between the UK IPO and the EPO are real. For example, the UK Manual of Patent Practice as revised in July 2010 states at 1.22.1:

“Thus a game implemented on a conventional computer system or network would be excluded as both a scheme, rule, or method for playing a game and a computer program as such.”

In contrast, EPO practice is to grant patents for computer games where a technical problem can be identified, as in T 717/05 LABTRONIX CONCEPT INC./Auxiliary game where the Appeal Board acknowledged a technical problem in terms of maintaining the player’s interest; see also T 1225/10 NINTENDO/Game program and  T 1769/10 IGT/Internet remote game server. It is to be hoped that ways can be found of reducing the possibility of real differences in outcome within the established UK approach which it seems will continue to be followed.

As a practical matter, applicants will also note the effect this decision has on patent strategy in the UK and in particular on the perceived value of patents in this area:

(a)    Patent coverage for the software would control its distribution and use which if unauthorised would now be a direct infringement of the patent. Such coverage can be obtained by claims to the software itself and on computer-readable media, see Astron Clinica v Comptroller-General [2008] R.P.C. 14; [2008] EWHC 85 Pat Ct. Further, and in contrast to the position in the US, signal claims are allowable in the UK and Europe and can control distribution via the Internet. US applicants should be advised to include basis for such claims in their US first filed applications and in any subsequent UK, European and International applications, otherwise it may be difficult to add such claims during prosecution owing to the well-known added subject-matter issues of a.123(2) EPC.

(b)   Claims to the design method as in Halliburton would arguably cover the direct product of that method i.e. the design data produced by that method, and would provide additional opportunities to control the distribution and use of that data.

(c)    Claims to the overall manufacturing process remain valuable and should be included since the licensing revenue (or potential infringement damages) arising at the manufacturing stage may be considerable.

Lucas & Co.



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