Re Halliburton Energy Services Inc

This is an appeal from the Comptroller-General of Patents relating to the patentability of computer implemented inventions.

The appellant (Halliburton Energy Services Inc.) made four patent applications before the UK IPO. They were all rejected on essentially the same grounds, that the inventions were excluded from patentability as schemes, rules or methods for performing a mental act and as computer programs. The first three applications were dealt with together at a hearing on 29th November 2010 before Mr Thorpe, Deputy Director acting for the Comptroller. He gave his decision in writing on 25th February 2011 (O/080/11). The fourth application (GB 0802302.0) was dealt with afterwards by Mr Thorpe on the basis of the papers already filed because the patentability question was the same as that considered in the 25th February decision. Mr Thorpe’s written decision rejecting that latter case was given on 19th May 2011 (O/170/11).

Halliburton appealed to the Patents Court and the matter came before me on 28th July 2011. Mr Richard Davis appears for Halliburton instructed by the patent attorneys Hoffmann Eitle. Mr Thomas Mitcheson appears for the Comptroller instructed by the Treasury Solicitor.

Mr Davis submitted that Mr Thorpe’s decision was wrong in law following the existing approach to patentability questions as set out by the Court of Appeal in Aerotel v Telco / Macrossan’s Application [2007] RPC 7 and Symbian v Comptroller [2009] RPC 1. In this respect he submitted that Mr Thorpe had construed the mental act exclusion too widely. He also submitted that the approach to patentability taken in the UK at present was in conflict with the approach taken in the European Patent Office. In the EPO at least one of his client’s applications had been examined without much of a murmur and this, he submitted, highlighted the difference between the UK and the EPO in this area of patent law. Mr Davis invited me not to follow Aerotel on the footing that it was not in accordance with the approach of the EPO. He contended that although when the matter came before the Court of Appeal in Symbian in 2008 there had not been a decision of the EPO Enlarged Board of Appeal on the point, in May 2010 the EPO Enlarged Board of Appeal handed down their opinion G3/08, concluding in effect that the EPO’s approach was indeed a settled one. He submitted I was not bound by Aerotel in any event because since Aerotel the Patents Act 2004 had amended the Patents Act 1977 to bring it into line with the amended European Patent Convention known as EPC 2000. EPC 2000, submitted Mr Davis, amended the law of patentability in a material way as compared to the relevant provisions considered in Aerotel.

Mr Mitcheson supported the decision of Mr Thorpe. He contended that the applications were not patentable. He submitted that I should follow Aerotel and that the changes in the legislation do not justify the course proposed by Mr Davis. He submitted that Mr Thorpe’s construction of the mental act exclusion in s1(2) was the right one as a matter of law.

Thus this case raises head on the question of the correct scope of the mental act exclusion in the 1977 Act. It is a point which has arisen in a number of cases before and on which there is conflicting authority. In order to deal with it in context, it will be necessary to deal with the way in which the patentability of computer implemented inventions is addressed in the UK more generally.

However before dealing with the substance of the case at all I need to deal briefly with a submission by Mr Davis about the nature of this appeal.

CPR Part 52 r52.11 provides as follows:

By r52.11(1) every appeal will be limited to a review unless either condition (a) or (b) is satisfied. It has been clear hitherto that in general appeals from the Comptroller of this kind are reviews rather than re-hearings (see Reef Trade Mark [2003] RPC 5 (CA), Blacklight Power Inc v Comptroller [2009] RPC 6 (Floyd J), and Patent Office Practice Notice 1/2003 paragraph 10 [2003] RPC 46). However Mr Davis submitted this appeal was by way of a rehearing and not a review because of the combined effect of the reference in r52.11(1)(a) to a practice direction making a different provision and then the terms of paragraph 9 of the Practice Direction 52 - Appeals. That paragraph states:

He submitted that paragraph 9.1(1) applied to the appeal from the second decision because no hearing took place. He also submitted that paragraph 9.1(2) applied to both appeals because the procedure did not provide for the consideration of evidence. In my judgment Mr Davis is wrong on both counts.

As regards 9.1(1), it would be absurd if that provision were to be interpreted in such a way as to cover the appeal from the second decision in this case. The second decision is one in relation to which Halliburton had the unfettered right to a hearing before the decision was made. Halliburton sensibly chose not to exercise their right to a hearing because there was no point in the circumstances. That pragmatic choice cannot be said to have given rise to such a fundamental change in the nature of the proceedings as would justify a re-hearing on appeal.

As regards 9.1(2), the point is simply wrong. An applicant is entitled to put evidence before the Comptroller if they wish. The fact that it is rarely done and that Halliburton did not do it on this occasion is not the point.

Thus neither limb of paragraph 9 of Practice Direction 52 applies in this case and so r52.11(1)(a) does not apply either. This appeal is a review. I should add that in a case of this kind I cannot see how the distinction between a review and a re-hearing makes any difference.

The case proceeded before me on the basis that all four applications stand or fall together. In my judgment that is right as regards the issues which fall to be dealt with on this occasion. It is therefore only necessary to consider one of them and, like Mr Thorpe, I will consider application GB 0523735.9 (referred to as ‘735).

The ‘735 application was filed on 22 November 2005 and published as GB 2420433 A on 24 May 2006. The invention is concerned with improving the design of roller cone drill bits for drilling oil wells (and the like). The point is to increase their drilling efficiency and their operational life. The invention uses a computer simulation of the interaction of the drill bit with the material being drilled to optimise various design features of the drill bits. The use of computer simulation reduces or eliminates extensive field testing. A fairly detailed description of the invention is set out in paragraphs 5 to 12 of Mr Thorpe’s decision. Neither side criticised those paragraphs. I will not repeat them. For the purpose of this appeal it is only necessary to consider claim 1.

Claim 1 in the form to be considered on this appeal is set out below (I have added numerals for ease of reference):

Thus the claim is to a method of designing a drill bit. The basic steps of the method are features (ii) to (vii). An initial drill bit design is specified by a user at step (ii). In step (iii) the computer simulates the drilling of the earth formation by that drill bit. This simulation includes taking into account the drill bit design and also at least one drilling parameter such as rate of penetration. In step (iv) the drill bit design is modified by the user in respect of at least one of the parameters making up the design. In step (v) the computer then simulates the drilling of the same earth formation using the same drilling parameter but with the modified design. This allows the user (step (vi)) to compare the simulated drilling performance of the two designs. The results are then “outputted” to a resource (step (vii)), such as a computer printer. Features (viii) to (xiv) define in detail how the computer carries out the simulation of the drilling task, using a form of finite element analysis.

A number of observations are important at this stage. First although the ultimate point of all this design and simulation work is no doubt to make a drill bit to the optimised design, the claim does not include the step of manufacturing a drill bit to the design. If the claim was amended to include such a feature then Mr Mitcheson accepts (I think) that it would satisfy the requirements of patentability with which this case is concerned. However Halliburton do not wish to include such a limitation. They contend it is unnecessary and the claim is fine without it. One might think it would be a small price to pay and wonder why we are bothering with all of this. However Mr Davis was at pains to submit that a claim limited in that way would not give his client realistic commercial protection for their invention. In the end of course Halliburton’s motives are irrelevant but it does seem to me that Mr Davis’ point is at least not fanciful.

Second, the claim includes the step of “outputting to a resource” (step (vii)). Such a feature is present in all the relevant claims of the four parallel cases. There is a debate as to whether those words in this claim (but not the others) amount to added matter. It is common ground that that point is not live before me. If I allow the appeal it is common ground that the matter should be remitted to the Comptroller for further consideration, when points like that can be dealt with if necessary.

Third, there was an important dispute between the parties on the true construction of this claim and in particular of output step (vii). The issue applies to all the relevant claims but can be decided on this one. It is perfectly obvious, and would be obvious to any skilled reader of the patent, that the invention involves the use of a computer. The simulations are to be run on a computer (see my summary of how the claim works above). However the claim never uses the word “computer”. Of course some steps in the method are intended to be carried out by a person (such as step (ii)) but others are not (such as step (iii)). Mr Mitcheson submitted however that the claim was not limited in such a way that a computer was mandatory; he contended that, as drafted, the crucial simulation steps (such as step (iii) and so on) could cover simulations performed by a person without a computer at all. Mr Davis submitted that the “resource” in the phrase “outputting to a resource the results of the method” (step (vii)) would be understood to be a computer resource - such as a printer or a computer memory - and so in fact the claim is limited to performance of the simulations on a computer. He said that his clients certainly wished the claim to be limited to a computer implemented method and had no desire to cast the claim any wider, such that if I was against him on the point of construction, he sought leave to amend the claim to put the matter beyond doubt.

In my judgment the skilled reader would understand perfectly well that the simulations referred to in claim 1 are computer simulations from reading the specification as a whole. I also note that the simulations being “computer simulations” is expressly referred to from p21 line 30 - p24 line 23 in the specification. Moreover the reader would understand that “outputting” to a “resource” is something computers do, not people. Accordingly I find that claim 1 (and its brethren) are limited to carrying out the simulations on a computer. They are computer implemented methods.

Nevertheless there is no doubt the claim could be more clearly drafted and if the application is to go further the examiner may wish to consider whether the claims could be more clearly expressed in this respect (bearing in mind s14(5)(b) of the 1977 Act).

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.

Sub-sections (1) and (2) of section 1 of the 1977 Act provide as follows:

These two sub-sections are among the statutory provisions that are specifically mentioned in s.130(7) of the 1977 Act. They should have the same effect as the relevant provisions of the EPC. In its current form (EPC 2000) those are in article 52, as follows:

Much ink has been spilt and many words spoken at conferences in seeking to interpret these provisions and to find a consistent and reproducible way of applying them. In Aerotel Jacob LJ (giving the judgment of the court) considered the provisions as a whole at paragraph 9. He explained that there is no evidence of an underlying purpose behind the provisions as a group and nothing to tell you one way or another whether they should be read widely or narrowly. The categories form a disparate group with no common, over arching concept. Some categories are given protection by other intellectual property laws and some categories are really so abstract as to be meaningless (how could a scientific theory ever be patented in the first place?).

However at the heart of the law is the consistent principle that an inventor must make a contribution to the art (that is to say the invention must be new and not obvious) and that contribution must be technical in nature (susceptible of industrial application and not within one of the areas excluded by Art 52(2)). These are the words of Kitchin J as he then was in Crawford’s Application [2006] RPC 11, which was decided just before Aerotel reached the Court of Appeal and referred to the cases up to that point. If I may respectfully say so, I agree with him. In my judgment the observation remains true today taking full account of Aerotel and Symbian as well as the other cases decided at the Patents Court level since.

The modern approach to dealing with the exclusions from patentability is that laid down by the Court of Appeal in Aerotel. Jacob LJ, giving the judgment of the court, said that the court should adopt a four stage approach to dealing with issues of this kind, namely:

As Jacob LJ made clear in Aerotel itself and as Lord Neuberger (giving the judgment of the Court) emphasised in Symbian (paragraph 8), the decision in Aerotel did not purport to represent a new departure in domestic law, not least because the court was, at least prima facie, bound, and indeed it regarded itself as bound, by the approach adopted in the three previous decisions of the Court of Appeal, namely Merrill Lynch [1989] RPC 561, Gale [1991] RPC 305, and Fujitsu Limited's Application [1997] RPC 608. Moreover as Jacob LJ explained (Aerotel paragraph 41) the four stage approach is simply a reformulation in a different order of the test applied in Merrill Lynch itself.

The difficulties in this area arise mostly in relation to inventions which involve the use of computers. All the Court of Appeal cases (from Merrill Lynch to Symbian) are about inventions implemented in software. The simple problem is that computer programs (as such) are excluded by s1(2)(c) (c.f. EPC Art 52(2)(c) and 52(3)) . Whether it was so clear in the past however, one thing is clear today. An invention which makes a contribution to the art which is technical in nature (to echo Kitchin J’s words in Crawford) is patentable even if it is implemented entirely on a computer and even if the way it works is entirely as a result of a computer program operating on that computer. The outcome of the Symbian case proves that.

Also, in Symbian (paragraphs 48 to 51) the Court of Appeal made it clear that there has been a consistent line of jurisprudence in this area following Vicom (T6/83), including Merrill Lynch and Gale and that it should be followed today. The change in approach by the EPO Boards embodied by Pension Benefit (T931/95), Hitachi (T2587/03) and Microsoft/data transfer (T424/03) should not be followed. Lord Neuberger (giving the judgment of the court) said this:

Thus when confronted by an invention which is implemented in computer software, the mere fact that it works that way does not normally answer the question of patentability. 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 which makes a contribution to the art which is technical in nature, is a patentable invention and may be claimed as such. Indeed (see Astron Clinica [2008] RPC 14) in those circumstances the patentee is perfectly entitled to claim the computer program itself.

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 (see Symbian paragraph 53 above). Clear examples are from the cases involving computers programmed to operate a method of doing business, such as a securities trading system or a method of setting up a company (Merrill Lynch and Macrossan). Inventions of that kind are held not to be patentable but it is important to see why. They are more than just a computer program as such. For example, they self evidently perform a task which has real world consequences. As Fox LJ said in Merrill Lynch (p569 at line 27), a data processing system operating to produce a novel technical result would normally be patentable. However that is not the end of the analysis. He continued: “however it cannot be patentable if the result itself is a prohibited item” (i.e. a method of doing business). When the result or task is itself a prohibited item, the application fails.

The reasoning in Merrill Lynch means that the computer implemented invention claimed there would not have been excluded from patentability if it were not for the combined effect of two exclusions in s1(2) - computer programs and (in that case) business methods. The cases in which patents have been refused almost always involve the interplay between at least two exclusions. A notable exception is the outcome of Fujitsu. However the Court of Appeal in Symbian drew attention to that case as having an arguably inconsistent result (in the passage quoted above and see also paragraph 42 of the judgment) and I note that Fujitsu is not mentioned in the important sentence at the end of paragraph 51 of Lord Neuberger’s judgment.

The business method cases can be tricky to analyse by just asking whether the invention has a technical effect or makes a technical contribution. The reason is that computers are self evidently technical in nature. Thus when a business method is implemented on a computer, the patentee has a rich vein of arguments to deploy in seeking to contend that his invention gives rise to a technical effect or makes a technical contribution. For example the computer is said to be a faster, more efficient computerized book keeper than before and surely, says the patentee, that is a technical effect or technical advance. And so it is, in a way, but the law has resolutely sought to hold the line at excluding such things from patents. That means that some apparently technical effects do not always count. So a computer programmed to be a better computer is patentable (Symbian) but as Fox LJ pointed out in relation to the business method exclusion in Merrill Lynch, the fact that the method of doing business may be an improvement on previous methods is immaterial because the business method exclusion is generic.

The Aerotel approach is a useful way of cutting through the cases like Merrill Lynch, Macrossan and Gale in which more than one exclusion is engaged. Take a patent claim consisting of a claim to a computer programmed to perform a business method. What has the inventor contributed? If the answer is a computer program and method of doing business and there is nothing more present, then the contribution falls solely within the excluded subject matter. It can be seen not to be patentable at step 3, before one gets bogged down in the argument that about whether a book keeping system running more efficiently on a computer is a technical effect. Following Aerotel the question has answered itself.

The “better computer” cases - of which Symbian is paradigm example - have always been tricky however one approaches this area. The task the program is performing is defined in such a way that everything is going on inside the computer. The task being carried out does not represent something specific and external to the computer and so in a sense there is nothing else going on than the running of a computer program. But when the program solves a technical problem relating to the running of computers generally, one can see that there is scope for a patent. Making computers work better is not excluded by s1(2).

What if the task performed by the program represents something specific and external to the computer and does not fall within one of the excluded areas? Although it is clear that that is not the end of the enquiry, in my judgment that circumstance is likely to indicate that the invention is patentable. Put in other language, when the task carried out by the computer program is not itself something within the excluded categories then it is likely that the technical contribution has been revealed and thus the invention is patentable. I emphasise the word “likely” rather than “necessarily” because there are no doubt cases in which the task carried out is not within the excluded areas but nevertheless there is no technical contribution at all.

So in Merrill Lynch and Macrossan the computer programs were unpatentable because the task the program performed was a business method. In Gale the program was unpatentable because the task it performed was a mathematical method (albeit the reasoning was the other way round, starting from the mathematical method rather than the computer program aspect).

This Aerotel approach is the way in which Mr Thorpe dealt with the applications before him. He sought to see if there was anything outside an excluded category present in the patentee’s contribution. He identified the contribution in paragraph 29 of his decision and considered in detail whether it fell within the mental act exclusion in s1(2). He considered the matter in great detail (paragraphs 31 to 74) and held that it was excluded. He considered the computer program and mathematical method exclusions much more shortly. He did not think the inventions were excluded as mathematical methods (paragraph 97) but just as they were excluded by the mental act exclusion so they were also excluded by the computer program exclusion. As Mr Thorpe said (paragraph 101):

In my judgment Mr Thorpe’s decision is an entirely orthodox application of the law subject only to the question of the width of the exclusion of a scheme, rule or method for performing a mental act. The question is whether Mr Thorpe’s decision as regards the scope of the mental act exclusion was right.

There are essentially two possible interpretations of this exclusion, a wide one and a narrow one. The wide construction is that a method is “a scheme, rule or method for performing a mental act” if it is capable of being performed mentally regardless of whether, as claimed, it is in fact performed mentally. Read this way the exclusion excludes methods of the type performed mentally regardless of how they are claimed. So 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 excluded by the mental act exclusion because calculations are the kind of thing which are capable of being performed mentally. On the wide construction this conclusion follows even though, as claimed in this example, the invention clearly does not cover performing the calculation mentally at all because the claim is limited to using a computer. This wide construction is the one which Aldous LJ favoured provisionally in Fujitsu (see p619 line 10 - 621 line 30).

The narrow construction is that the exclusion only excludes acts carried out mentally. On the narrow construction a claim to a calculation carried out on a computer could never be caught by the mental act exclusion because the claim does not encompass carrying out the calculation mentally. The fact that calculations in general are the kinds of thing which are capable of being performed as mental acts is irrelevant. This narrow interpretation is the one favoured by Jacob LJ in Aerotel, doubting the views of Aldous LJ on this point in Fujitsu. As Jacob LJ said (in paragraph 98 of Aerotel):

In this case Mr Thorpe applied the wide construction. If the wide construction is right then the ‘735 claim is excluded from patentability and subject to Mr Davis’ submission that I should rejected the Aerotel approach altogether, the appeal should be dismissed.

Mr Thorpe followed the wide construction to mental act because he understood he was bound to do so by the judgment of Pumfrey J in Halliburton v Smith [2006] RPC 2. That case had striking parallels to this one. Halliburton’s patent was for another method of designing a roller cone drill bit. The relevant claims are set out in paragraph 64 of the judgment. The claims did not contain any express reference to the method being carried out on a computer nor did they contain an express “output to a resource” step. Nevertheless Mr Mitcheson submitted that Pumfrey J had construed the claims such that they in fact included an output step to a computer file known as a “computer aided design” or CAD file. I am not certain Mr Mitcheson is right about that. The paragraph Mr Mitcheson relies on (paragraph 94) does indeed describe the result of the claimed method as being a CAD file and includes the words “if I am right on the question of construction” but in the same paragraph Pumfrey J then refers to the CAD file being input to a numerically controlled milling machine to produce cones and refers to the cones being assembled into a bit body. This paragraph was concerned with the question of infringement of the method claim under s60(1)(c) of the 1977 Act (product obtained directly by means of the process) and in that context it can be readily understood. To deal with s60(1)(c), the result of carrying out the claimed process has to be identified. I do not think Pumfrey J was reading into the claim itself a feature (output to a CAD file) which is simply absent from the language.

Pumfrey J addressed the mental act point at paragraph 207 to 218. He acknowledged the judgment on mental act in Fujitsu and then said the following:

Thus Pumfrey J followed closely on the EPO’s approach in VLSI Chip Design T 453/91. There a claim to a method of designing a silicon chip was not allowed but the patentability problem was solved simply by adding the words “and materially producing the chip so designed” at the end of the claim. So in the case before Pumfrey J the claimed method of designing a drill bit was “firmly within the forbidden region as schemes for performing a mental act” but that this problem could be cured by an amendment of a similar type (such as adding the words “and making the drill bit so designed”).

Mr Thorpe understood that Pumfrey J was adopting the wide construction of the mental act exclusion. He is in good company since Jacob LJ in Aerotel said:

With respect to Jacob LJ (and taking due account of the fact that his observation was no doubt aided by a submission by counsel appearing before him on that occasion) I am not certain that Pumfrey J was adopting a wide construction of the mental act exclusion. It seems to me that the reasoning in paragraph 217 of Pumfrey J’s judgment is based on the narrow construction. In paragraph 217 Pumfrey J reasons in the following way. As drafted the claims are directed to the purely intellectual content of the design process. Although the invention is really about using a computer program, to be precise the claims are not limited in terms to a computer program. Thus they are firmly within the forbidden region as schemes for performing a mental act because they are not limited in terms to a computer program. This reasoning appears to me to be based on the narrow approach to mental acts. The exclusion is only relevant because the claims are so wide that they can be performed mentally.

However whichever approach Pumfrey J was taking, the fact that he regarded the problem as curable by an amendment to add in the step of making a drill bit is important. Another perennial issue in this area of the law is the distinction between matters of form and matters of substance. It is well established in the UK that one cannot avoid the computer program exclusion simply by claiming a computer suitably programmed (see Merrill Lynch and Gale). So Pumfrey J recognized that it could be said that the amendment he required did not affect the position as a matter substance. He did not accept that however because in his view the objection itself was to the form of the claim and not to the substance of the invention. He held that the method “had an industrial utility, that is a potential technical effect”. Designing drill bits is after all an industrial activity. The objection was as to form - that the claims were so broadly drafted and “untethered” to be within the forbidden region as a scheme for performing a mental act. Once that formal problem was cured, the objection fell away.

In any event, after Aerotel (which, insofar as Pumfrey J had taken a wide view of mental act in Halliburton v Smith, had doubted it was correct) Pumfrey J returned to the mental act issue in his judgment in Cappellini / Bloomberg [2007] FSR 26. At paragraphs 7 and 8 he said as follows:

Mr Mitcheson submitted that the reference in paragraph 8 above to an “algorithm capable of being performed by a human being mentally” meant that Pumfrey J was maintaining the wide construction of the mental act exclusion. I do not agree. For an algorithm to be a scheme for performing a mental act Pumfrey J required two things, first the algorithm must be capable of being performed mentally and second it must be complete when the algorithm terminates so far as the claim is concerned. The second condition is a reference to the judge’s earlier point that a claim in the objectionable form was not limited to being performed by a computer and, without amendment, would have been infringed had the person employing the method stopped at the end of the necessary calculations. Such a claim could be cured by an appropriate amendment to make sure that it could not be infringed by a person working alone. Therefore in this passage Pumfrey J was certainly not adopting the wide construction of the mental act exclusion. It seems to me he was adopting a narrow one.

The mental act exclusion came up again in Kapur [2008] EWHC 649 (Pat) before Floyd J. In this judgment Floyd J again reviewed the same line of authorities (now up to and including Cappellini) and held that the narrow view of the mental act exclusion was the right one. Floyd J said:

There is no question that this is part of the ratio of Floyd J’s judgment since it was a crucial part of his reasoning which led to the overturning of the decision of the Hearing Officer on the point (see paragraph 37) and the basis for this part of the case being remitted back to the Comptroller (paragraphs 38 and 39). Regrettably this clear judgment does not appear to have been drawn to Mr Thorpe’s attention in the present case.

The final case to consider in this line is Symbian [2009] RPC 1 (Court of Appeal). The Court were not concerned with the ambit of the mental act exclusion but it was mentioned in relation to Fujitsu. Lord Neuberger (giving the judgment of the court) indicated that the court had some difficulty reconciling the outcome of the Fujitsu case in relation to what constitutes a technical contribution with earlier decisions but stated that ‘the actual decision in Fujitsu may well have been justified on the alternative ground tentatively relied on by Aldous LJ, namely that the alleged invention was a “method for performing mental acts”’ (paragraph 42).

Now the Court of Appeal were not considering the ambit of the mental act exclusion at all in Symbian and the sentence I have quoted is all that is said on the topic. However it would be disingenuous not to face up to the fact that Lord Neuberger’s suggestion only works if the wide approach to the mental act exclusion is taken, as was tentatively proposed by Aldous LJ in Fujitsu itself, but which has been doubted in later cases. That is because in Fujitsu at least some of the claims could not be infringed by mental acts alone (see claims 9 and 10 at p613 of the report). Indeed claim 9 of Fujitsu is a claim “tethered” to a manufacturing step (compare Hallibuton v Smith). Does this sentence in Symbian mean that the judgment of Floyd J in Kapur has been overruled or even seriously doubted or that the reasoning subsequent to Fujitsu on mental acts in Aerotel and Cappellini has been undermined? In my judgment it does not. The ambit of the mental act exclusion was just not before the Court of Appeal in Symbian. They were not focused upon it and its scope was not a necessary part of the court’s reasoning.

So the balance of authority in England is in favour of the narrow approach to the mental act exclusion. I will only add that, if the matter were free from authority, I would favour the narrow interpretation on its own merits. The wide construction seems to me to be uncertain in scope and I am not aware of any good reason why the exclusion needs to be interpreted widely. On the other hand I can see a logic behind the narrow interpretation, preventing patents being granted which could be infringed by a purely mental process. Allowing for the possibility of patent infringement by thought alone seems to me to be undesirable.

What of the EPO? For that Mr Davis cited decision T1227/05 (Infineon) of 13th December 2006.

The Board in Infineon regarded the scope of the mental act exclusion as narrow. The Examining Division had rejected the application because the simulation method claimed (as the claims then stood) constituted a mental act or mathematical method. However on appeal the Board indicated that a computer implemented embodiment of that method would overcome the objection. The claims were duly amended and as I understand the decision (see Summary of Facts paragraphs I - III) the introductory words of claim 1 were in effect changed from “Method for the numerical simulation of a circuit …” to “Computer-implemented method for the numerical simulation of a circuit …”. Thus in paragraph 3.2.1 of the decision the Board said:

This is the same as the reasoning of Floyd J in Kapur. If the claim cannot be performed by purely mental means, the exclusion is irrelevant.

It may be noted that in Infineon the Board followed the EPO’s general approach to patentability which was doubted in Aerotel and so considered whether various elements of the claim were technical in nature in order to assist the Examining Division in relation to inventive step once the case was remitted following the appeal. However this has nothing to do with their views of the scope of the mental act exclusion itself. The difference between the EPO and the UK is not directed to the width of the exclusions in Art 52 / s1(2) themselves, it is concerned with the place in the analysis that they come into play. Therefore the Board’s view on the scope of the mental act exclusion is relevant.

The further significance of this decision from Mr Davis’ point of view is that the EPO Technical Board of Appeal revisited the earlier VLSI Chip Design/ IBM decision T453/91 which Pumfrey J had followed in Halliburton v Smith as requiring the introduction of an amendment to include a manufacturing step into a claim to a method of designing something. In Infineon the Technical Board of Appeal held that a manufacturing step was not necessary (as long as the claim did not otherwise fall foul of the patentability requirements). They held that computer implemented simulation methods can themselves be regarded as modern technical methods and should not be denied a technical effect just because a physical end product is not incorporated in the definition of the method steps. The relevant part of the decision (paragraph 3.4) also states that this view is in line with a decision of the German Federal Court of Justice of 13th December 1999 (X ZB 11/98 Logikverifikation).

In my judgment the correct scope of the mental act exclusion is a narrow one. Its purpose is to make sure that patent claims cannot be performed by purely mental means and that is all. The exclusion will not apply if there are appropriate non-mental limitations in the claim.

Accordingly when Mr Thorpe applied the mental act exclusion to this case he did so on too broad a basis and his decision is ill founded.

Properly construe the claim;

I have construed the claim above. Importantly and unlike the facts of the case arising in Halliburton v Smith, in my judgment in this case the claim is limited to a simulation process carried out on a computer. In that respect it is similar to the claim allowed by the Technical Board of Appeal in Infineon. Although the claim in this case could be better drafted, it is in fact a claim to a computer implemented method.

Identify the actual contribution;

Mr Thorpe identified the contribution made by this invention in paragraph 29. He said:

I agree with that statement save that it seems to me to be important to state that the contribution is a computer implemented method of designing drill bits. Normally that emphasis would not be very important, for example if the case was concerned with the business method exclusion it would be irrelevant, but in this case, given the debate about the mental act exclusion, it is critical.

Ask whether it falls solely within the excluded subject matter;

Mr Thorpe’s view was that the case before him could not be distinguished from Halliburton v Smith and that as a result the claim would not be patentable at least unless it was “tethered” by an amendment to add a manufacturing step. Since no such amendment was before him, he held the claim was not patentable. Mr Thorpe was also concerned that he could not see how such an amendment could in fact overcome the objection as a matter of substance in any event but since no such amendment was before him, he did not have to grapple with that problem (see decision paragraphs 65-66).

In my judgment Mr Thorpe’s difficulty with how a manufacturing step could make a difference stems from the wide view of the mental act exclusion, which I have held to be wrong. Indeed it seems to me that his difficulties in seeing how any amendment could overcome the wide view are another reason for doubting the correctness of the wide view.

Approached on the correct, narrow basis, the mental act exclusion is irrelevant in this case. The claimed method cannot be performed by purely mental means and that is the end of the matter. Put another way, the contribution is a computer implemented method and as such cannot fall within the mental act exclusion.

That does not mean it is necessarily immune from the computer program exclusion but that is a different matter. Is it more than a computer program as such? The answer is plainly yes. It is a method of designing a drill bit. Such methods are not excluded from patentability by Art 52/s1(2) and the contribution does not fall solely within the excluded territory. Drill bit design is not a business method, nor a scheme for playing a game nor (as I have held) is this claim a scheme for performing a mental act.

Mr Mitcheson did submit that the method was a mathematical method. I note that Mr Thorpe did not think so. No Respondent’s Notice was filed but Mr Davis was content to deal with the point in any event. I agree with Mr Thorpe. Although obviously some mathematics is involved, the contribution is not solely a mathematical method (on top of being a computer program) because the data on which the mathematics is performed has been specified in the claim in such a way as to represent something concrete (a drill bit design etc.). That is an important difference between the position in Gale and the position here. In Gale the claim was broadly drafted and it was nothing more than a mathematical method implemented on a computer.

In my judgment Aerotel question 3 can be answered in Halliburton’s favour.

Check whether the contribution is actually technical in nature.

This is not a case in which the cross-check at step 4 presents any difficulties. Designing drill bits is obviously a highly technical process, capable of being applied industrially. Drill bit designers are, I am sure, highly skilled engineers. The detailed problems to be solved with wear and ability to cut rock and so on are technical problems with technical solutions. Accordingly finding a better way of designing drilling bits in general is itself a technical problem. This invention is a better way of carrying that out. Moreover the detailed way in which this method works - the use of finite element analysis - is also highly technical.

It is clear that Pumfrey J regarded the method of designing drill bits in the case before him in Halliburton v Smith as “freighted with the technical effect that is needed for patentability” (see paragraph 217). His concern was not with the technical contribution as a matter of substance - which he did not doubt - but with the form of the claims (paragraph 218). It seems to me that there is no difference between that case and this one in this crucial aspect.

In my judgment claim 1 of ‘735 satisfies the requirement of patentability following the Aerotel approach.

Looked at another way and echoing Crawford, for the purposes of this appeal I can assume that the invention is new and not obvious since those points are not before me. Thus the invention makes a contribution to the art. That contribution is obviously susceptible of industrial application and, based on my findings of law, not within one of the areas excluded by Art 52(2). Thus the contribution is technical in nature and the invention is patentable.

In the Comptroller’s Practice Note issued on 2nd November 2006 following Aerotel at paragraph 13, the differing judicial comments on the scope of the mental act exclusion as between Fujitsu and Aerotel were noted. The paragraph indicated that Examiners would lean towards the view expressed in Aerotel. In other words the Examiners were (at least tentatively) going to follow the narrow construction of the exclusion. Following Symbian the Comptroller issued a further Practice Note on 8th December 2008. Paragraph 8 addressed the mental act exclusion and referred back to paragraph 13 of the post Aerotel Practice Note. Paragraph 8 states “In future examiners will object to the computerisation of what would have been a pure mental act if done without the aid of a computer as both a mental act and a computer program as such”. This is the wide construction and so, as one would expect, Mr Thorpe’s decisions in this case are in accordance with the current Practice Note. The logic of the Practice Note is that, on the strength of Symbian, the Examiners were now to follow the wide approach to the mental act exclusion rather than the narrow one. However Symbian did not decide that question. My decision in this case means that the approach proposed to mental acts in paragraph 8 of the current Practice Note is wrong in law and should not be followed. (For that matter the same conclusion follows from the judgment of Floyd J in Kapur.)

Since I will allow the appeal, Mr Davis’ wider submissions, that the UK should now depart from Aerotel and follow the EPO’s approach as embodied by Pension Benefit, Hitachi and so on does not arise. I will only make the following brief observations about the issue:

The appeals will be allowed and the cases remitted to the Comptroller.