Environmental Defence Systems Ltd v Synergy Health Plc & Ors

This is the trial of a preliminary issue in an action for patent infringement. European Patent No. 2 393 989 (“the Patent”) claims a method of manufacturing barrage units, which are used for flood defences in a similar way to sandbags. In broad terms the method of the invention is to make water absorbent pads and then arrange them within a porous bag or sack, forming the barrage unit.

The Claimant (“EDS”) is the owner of the Patent and sells its patented barrage units under the name ‘Blastsax’ and ‘Floodsax’.

The First and Second Defendants, who need not be distinguished and whom I will collectively call ‘Synergy’, are manufacturers and suppliers of healthcare products. On 1 July 2008 EDS and Synergy entered into an agreement by which Blastsax and Floodsax barrage units were manufactured by Synergy and supplied to EDS. That agreement came to an end in June 2011.

It is common ground that since about 1994 Synergy has been making absorbent pads according to the method for making such pads described in the Patent, using what was referred to as the ‘Sanpro’ machine. At least until 2007 these were used solely for healthcare purposes, in particular as incontinence pads.

The Third Defendant is a manufacturer and supplier of flood defence products including substitutes for sandbags. The Fourth and Fifth Defendants are officers of the Third Defendant. I will refer to them collectively as ‘Gravitas’. Gravitas sells sandbag substitutes for use in flood defences and for non-flood purposes such as stabilising temporary traffic signs. They are sold under the trade names ‘HydroSack’, ‘HydroSnake’, ‘ TrafficSack’ and ‘Hydro-pad’. It is common ground that these were made using absorbent pads supplied to Gravitas by Synergy and that the absorbent pads were made according to the method described in the Patent. EDS claims that in consequence both Synergy and Gravitas have infringed the Patent.

One of the matters raised by Synergy in its Defence is that from about 2007, before the priority date of the Patent (19 November 2009), they had not merely been making absorbent pads as described in the Patent, they had been taking the further step of sewing the absorbent pads into bags and thus performing the totality of the claimed invention. This led to points pleaded in relation to s. 64 of the Patents Act 1977 (right to continue an act done before the priority date) and s.72(1)(b) (a patent granted to a person who was not entitled to it). As emerged at the CMC on 17 December 2013, these and other pleaded points turned on a single issue. The parties sensibly proposed that this issue should be the subject of the trial as a preliminary point. Exceptionally, it was sufficiently likely in the present case that a judgment on the preliminary issue would save time and costs, so I ordered that the following be determined:

It is not in dispute that the method of manufacture of the absorbent pads formed part of the prior art at the priority date of the Patent. They were known to serve in particular as incontinence pads. The only issue I have to decide is whether there was an inventive step in using the known method of making the pads as part of a process for making barrage units as claimed in claims 1, 6 or 9 of the Patent.

That resolved into two sub-issues during the hearing. Although the inventions in each of claims 1, 6 and 9 were initially advanced as being independently inventive, it was not in the end submitted by EDS that there was a separate invention in claim 6. Attention was therefore focussed on claims 1 and 9. The sub-issues emerge from those two claims.

Claim 1 is:

Claim 9 claims:

The proposed inventive concept in claim 1 is the idea of using known absorbent pads in the manufacture of barrage units – as opposed to their use as incontinence pads and for similar healthcare purposes. As for claim 9, the claimed inventive concept is ‘arranging’ the pads in a porous bag or sack.

The experts from the two sides came from different fields. Mr Hay, who gave evidence for EDS, is the managing director of a company which makes and markets personal hygiene products, in particular incontinence pads and nappies. His expertise lay in making absorbent pads for use in that market. The defendants’ expert was Professor Penning-Rowsell who has been professor of geography at Middlesex University since 1984. He has particular expertise in the hazards of flooding and flood risk management.

There was a dispute as to which was the better placed to give evidence about the persons skilled in the art and by extension what the characteristics of the skilled person were in the present case. This raises a point of law and procedure.

The usual starting point for identifying the person skilled in the art is the well known passage in Catnic Components Ltd v Hill & Smith [1982] RPC 183. At 242-3 Lord Diplock set out the essential characteristics of the person skilled in the art: he or she is likely to have a practical interest in the subject matter of the invention and practical knowledge and experience of the kind of work in which the invention is intended to be used.

However as Jacob LJ pointed out in Schlumberger Holdings Limited v Electromagnetic Geoservices AS [2010] EWCA Civ 819; [2010] RPC 23 this sometimes needs to be treated with caution. In Catnic Lord Diplock was concerned only with the skilled person in the context of the construction of the claims – what would now be seen as an application of the Protocol to Article 69 of the European Patent Convention. While the characteristics of the skilled person in relation to insufficiency (Art 86 EPC) will be the same as those identified by Lord Diplock, this may not be true of the skilled person through whose eyes inventive step is to be assessed (Art 56). Jacob LJ referred to a number of cases which illustrate that the skilled person or team for considering inventive step may differ from the person or team used to address insufficiency or claim construction.

One of the cases was the decision of the Technical Board of Appeal (“TBA”) of the European Patent Office in T422/93 JALON/Luminescent security fibres [1999] EPOR 486. The claimed invention was a process for the manufacture of security threads by introducing luminescent rare earth chelates into the threads by a dyeing process. The closest prior art described threads containing the chelates homogeneously distributed in a mass and their preparation by extruding the mass in a spinning process to make the threads. The problem was to develop a different and better process for incorporating the chelates. The Opposition Division had held that the skilled person was drawn from the field of expertise in the dyeing of fibres, which indeed is what the patent itself stated. Given that the solution to the problem identified by the patent was incorporation of chelates by a standard process for dyeing fibres, there was no inventive step. On appeal the TBA rejected this, ruling that the claimed inventive step – using a dyeing process to introduce rare earth chelates – was only made obvious by the very idea of using the expertise of one skilled in dyeing fibres. That was part of the solution. The TBA said that the skilled person should come from the field of the prior art where the relevant prior art gave no indication that the solution to the problem was to be sought in another technical field. The TBA found that it was not obvious to such a person to use a dyeing process to incorporate the chelates and consequently there was an inventive step.

The point of principle which the TBA seems to have advanced in Jalon is that inventive step must always be considered through the eyes of a skilled person drawn from the field of the relevant prior art (unless there is an indication in that prior art pointing to another technical field).

This implies the possibility that two distinct skilled persons have to be hypothesised to address different tasks. The skilled person used to assess the scope of the claims or insufficiency is bound to have a practical interest and experience in the technical field to which the invention is directed. Of course where the alleged invention and the prior art come from the same or similar technical fields, there will either be no difference between the two skilled persons, aside from knowledge of the patent, or the difference will be too nuanced to matter.

The decision of the TBA in Jalon is considered good law in the EPO, see Case Law of the Boards of Appeal of the EPO, 7^th ed., 2013, I.D.8.1.1.

In Schlumberger the Court of Appeal referred to Jalon among other cases and confirmed that in some instances the technical backgrounds of the skilled person for inventive step on the one hand, and the skilled person for claim construction and insufficiency on the other, may not be the same. (The Court of Appeal left aside the skilled person through whose eyes prior art is to be considered for the purposes of an argument on lack of novelty, which did not arise). Although the same words, “person skilled in the art”, are used in each of Art 56, the protocol to Art 69 and Art 83, the “art” in question may differ in the context of Art 56 as opposed to the other two articles and thus the skilled person may differ (see [63]-[64]).

However in the context of Art 56 Jacob LJ, with whom Waller and Sullivan LJJ agreed, did not adopt what seems to be the rule in Jalon, namely that the skilled person must be drawn from the technical field of the relevant prior art. Certainly if a skilled person from that field would discern no inventive step having considered the prior art, the patent is invalid. But equally if a skilled person drawn from the technical field of the alleged invention would conclude there is no inventive step, having considered the same prior art, the patent is likewise invalid (see [53] and [66]).

What may not be done is to consider inventive step from the perspective of the two skilled persons jointly where one is drawn from the field of the prior art and the other from the technical field to which the patent is solely addressed. Invention may lie in joining two or more technical fields of expertise to address the problem. Creating inventive step in that way would wrongly neutralise the possibility of the assembled skilled persons perceiving the inventive step (see [50]). (For simplicity, I am still considering only a single skilled person, not a team).

Going back to Jalon, it seems to me that there are two possible reasons why the TBA took the view that the Opposition Division had been wrong to decide that there was no inventive step when the prior art was considered through the eyes of an expert in the dyeing of fibres. The first is the one I have already mentioned, namely that the TBA took the prescriptive view that in the context of inventive step a piece of prior art must be considered by a skilled person drawn from the same field as that prior art and no other (subject to the prior art prompting attention to be directed at a different art). To the extent that this reflects the current interpretation of Art 56 EPC by the EPO, there is a divergence between that interpretation and English law on inventive step as set out in Schlumberger. I am of course bound by the latter. The second possibility is that the TBA’s rejection of the decision at first instance turned on the fact that the Opposition Division found a lack of inventive step by reference to more than one item of prior art. Whether or not this was a central part of the reasoning, it anyway highlights that care must be taken when the argument on lack of inventive step depends on the combination of two or more pieces of prior art. If both lie outside the technical field of expertise of the person skilled in the art, combining their respective disclosures to arrive at the claimed invention is likely to be less obvious to such a person than to a skilled person with expertise in the field about which the prior art documents are concerned.

Returning to Schlumberger, as a matter of English law anyway there is nothing wrong in having the skilled person relevant for assessing construction of the claims or insufficiency also being put to work in assessing inventive step. Separately, his equivalent drawn from the field of the prior art can also be put to the same task. Obviousness in the eyes of either is fatal to the validity of the patent. Indeed it seems to me that the logic of this is that the skilled person could come from any technical field at all when inventive step is being considered. If a skilled person drawn from any technical field finds the claimed invention obvious having read an item of cited prior art, there is no inventive step.

The fact that the skilled person can be drawn from two or more technical fields highlights a principle of practice when considering inventive step, particularly in the IPEC. A party seeking to invalidate a patent, generally the defendant, proposes a shortlist of prior art. According to English procedure (unlike that of the EPO) it is not for the court to say whether the shortlist contains the closest prior art – the defendant must decide on its best shots. Taking the simple case (no combinations of prior art relied on) each cited piece of prior art will at trial be taken to have been read with interest by the skilled person in the light of his common general knowledge. That common general knowledge will depend on the technical field from which the skilled person is drawn. Since potentially there are alternative sets of common general knowledge, the defendant must say which technical field for the skilled person is being nominated and this must clearly be stated in the defendant’s pleading. The court may have to resolve certain characteristics of the skilled person, notably the level of his education and training and the precise content of his common general knowledge. But his technical field is a matter for the defendant to nominate in its pleading so far as inventive step is concerned.

Because of the nature of pleadings in the IPEC the defendant will have to go a good deal further than that: stating in brief its argument on inventive step following the guidelines of Pozzoli SpA v BDMO SA [2007] EWCA Civ 588; [2007] FSR 37, in particular at [23]. And even though the technical field of the skilled person for purposes other than inventive step is a matter of law rather than nomination, this must also be one of the matters pleaded. However here I have specifically in mind a clear statement of the skilled person’s technical background for assessing inventive step.

In response the patentee must also concisely set out its arguments in relation to inventive step, which should include addressing the common general knowledge of the skilled person drawn from the technical field selected by the defendant.

It should then follow that by the time of the CMC it is evident what sort of directions each of the parties is seeking and why, in particular with regard to expert evidence: how many experts need to give evidence and in which disciplines. I should say that even if the defendant pleads that skilled persons from more than one technical field are relevant due to a distinction between assessing inventive step and other matters, it does not at all automatically follow that more than one expert will be permitted. Evidence will always be kept to an appropriate minimum and the cost/benefit test set out in PD 63 paragraph 29.2(2) will be strictly applied. As Jacob LJ pointed out in Schlumberger (at [40]) in nearly all cases the notional skilled person or team will on the facts be the same for all purposes. Only in plain cases of a distinction on the facts between the skilled person regarding obviousness and regarding other purposes is it likely that two sets of experts will be contemplated. The point I wish to emphasise is that by the time of the CMC the parties’ contentions in this regard (and all others) must be clear so that the court is in a position to rule on whether expert evidence may be given and to identify the technical field or fields to which that evidence will relate. The parties can then select their expert witnesses from that field or those fields. From the CMC onwards these matters should be fixed for the purposes of the trial.

Regrettably that is not what happened in the present case. Synergy’s Amended Grounds of Invalidity pleaded reliance on common general knowledge among other things but said nothing at all about the person skilled in the art. Gravitas’s Amended Grounds of Invalidity did identify the technical background of the skilled person up to a point, who was to be the same for the purposes of inventive step and other matters. Paragraph 9 of the pleading said this:

EDS’s Reply and Defence to Synergy’s Counterclaim denied that the Patent lacked inventive step over the common general knowledge of the skilled person, but said nothing more about the skilled person. EDS’s Reply and Defence to Gravitas’s Counterclaim responded to paragraph 9 of the Counterclaim thus, at paragraph 32:

In summary, Gravitas pleaded that the skilled person was a manufacturer of absorbent products without saying whether he came from the personal hygiene or flood defence industry, Synergy said nothing and EDS pleaded that the skilled person was interested in environmental protection with a focus on barrage units. I regret to say that at the CMC on 17 December 2013 I did not notice this discrepancy, nor was it drawn to my attention. I gave each side permission to call one expert witness but the order did not state the technical subject matter to be addressed by the experts.

When it came to preparing expert evidence EDS, contrary to what it had pleaded, elected to call Mr Hay who was a man with expertise in the personal hygiene business and who knew a lot about absorbent pads for that purpose. For their part Gravitas also abandoned their pleaded case and went for an expert on flooding.

This was not satisfactory. EDS complained that the defendants’ change of heart was unfortunate; EDS had taken Gravitas at their word and called an expert along the lines proposed by Gravitas. I have some, though a limited amount of sympathy for EDS’s complaint. It was for the defendants to propose the technical field of the skilled person as part of its case. Gravitas did that up to a point. Synergy said nothing. EDS did not challenge this at the CMC. My impression is that both sides thought that details of the skilled person, including the technical field from which he came, was best left to be argued about at trial.

For the reasons I have given I think it should certainly not have been left until then. The practical consequence of the way that the proceedings progressed is that the defendants were not pinned down with regard to their nominated skilled person until they served their expert evidence. At this point, by implication, they had moved to the suggestion that the relevant field was similar to the background of Professor Penning-Rowsell. By the time of the trial this was their expressly stated case.

However, that is now the position and I have to consider the defendants’ attack on the validity of the Patent in the way it was put by the defendants at trial.

Common general knowledge is the technical background knowledge of the person skilled in the art. It includes all the information in the relevant field of which he would be aware and which he would regard as basic reliable information. His awareness may take the form of carrying it in his mind as part of his remembered stock of information, or he may be aware of it in the sense of knowing that it exists and being able readily to access it if he is prompted to do so, for instance by a piece of prior art, see Generics (UK) Ltd v Daiichi Pharmaceutical Co Ltd [2009] RPC 23, at [23]-[28].

In the present case the defendants’ case on lack of inventive step included the assertion that the skilled person came from the field of flood defences and the manufacture of a ‘sandless sandbag’ for use in flood defences. This included the implied assumption that sandless sandbags were known to the skilled person, which was not common ground. I therefore take the relevant technical field to be flood barrage units which may or may not have included items other than sandbags in November 2009. The relevant common general knowledge is that of a skilled person from such a field. This is not a case which calls for a skilled team.

There were only two witnesses, both experts. As I have mentioned, EDS’s expert was Mr Gerry Hay, managing director of a company that makes personal care products including incontinence pads and nappies. The expert for both Synergy and Gravitas was Professor Edmund Penning-Rowsell who has been professor of geography at Middlesex University since 1984. Professor Penning-Rowsell has particular expertise in the hazards of flooding and flood risk management.

Both witnesses gave their evidence clearly and were doing their best to assist the court. Their expertise is distinct. Mr Hay knows a great deal about the absorbent pads described by the Patent and their use over the years in the making of incontinence pads and nappies. He did not claim any expertise in flood defences. Professor Penning-Rowsell, by contrast, knows a lot about the nature and development of flood defences in this country in recent years but had no experience of manufacturing anything using absorbent pads, whether for nappies or barrage units.

Neither expert was in my view a close approximation of the person skilled in the art. This need not matter – the function of an expert witness is to educate the court, not to serve as a proxy skilled person. The value of an expert’s evidence will, however, always depend on his or her capacity to present accurately the perspective of the hypothetical skilled person.

Professor Penning-Rowsell has qualifications well above the level of the skilled person, a much wider breadth of interest and an academic, as opposed to practical, frame of mind. In my view the skilled person from the nominated technical field would have experience of making barrage units for flood defences, such experience certainly including the manufacture of sandbags but also extending to all types of barrage units that were within his common general knowledge in November 2009. He would be open to the possibility of improvements to barrage units but entirely unimaginative in that as in all other matters. Nonetheless, Professor Penning-Rowsell’s experience meant that he could give evidence as to the information circulating among those interested in flood defences in November 2009 and therefore potentially what would have been part of the skilled person’s common general knowledge.

Mr Hay, through no fault of his, was not in a position to assist in relation to the knowledge of the skilled person. He was not familiar with what those working in the area of flood defences would know.

The inventive concept proposed by EDS in claim 1 is the notion of using the method set out in that claim for making an absorbent pad in the manufacture of a barrage unit.

It seems to me that the question whether this comprises an inventive step turns on a short point. By common consent the skilled person is assumed to be informed of the manufacture of absorbent pads according to the means claimed in the Patent. Either he would have found this knowledge relevant to his interest in the manufacture of barrage units in that they might be used for such manufacture, or he would have dismissed it as irrelevant. If the former, there is no inventive step.

This is subject to the important proviso that the skilled person would not have rejected the idea as impractical. If he would have had no reasonable expectation of making a barrage unit of at least some practical use with absorbent pads as part of the manufacturing process, there is potentially an inventive step. EDS argued that the skilled person would have thought that absorbent pads work in quite a different way to the sand inside sandbags, which were the conventional flood defence at the priority date. Sand does not absorb much water and its purpose in bags is to act as a water block. On the other hand the function of absorbent pads in the personal hygiene industry is to absorb liquids. EDS submitted that the skilled person would have been sure to realise that no amount of pads inside a barrage unit could absorb all the flood water. That is presumably true, but I don’t think that by itself it raises an inference of an inventive step. EDS needed to go further and show that the skilled person would have thought that a barrage unit full of saturated and fully expanded absorbent pads would be of no practical value in blocking the flow of flood water. EDS could not advance this further argument because there was no evidence to support it.

So I turn to the evidence of whether the skilled person would in November 2009 have considered the idea of using absorbent pads in the manufacture of barrage units. The Patent itself at paragraphs [3] to [5] records that this idea was known at the priority date; it formed part of the prior art. However as counsel for EDS rightly submitted, that is not the same thing as being within the common general knowledge of the skilled person. The defendants’ case does not rest on the combination of two items of prior art, but on the application of common general knowledge to the prior art information regarding the making of absorbent pads.

Professor Penning-Rowsell’s evidence on this was in summary as follows. In November 2009:

There was a great deal of widely available information that would have told the skilled person of the character of a sandless sandbag.

Such information could have been obtained from the many flood fairs that had been organised in flood affected areas and would include the information that sandless sandbags contain a super-absorbent polymer, or similar material.

In addition there were items on the internet dating from before November 2009 relating to sandless sandbags, examples of which he annexed to his report. These stated that sandless sandbags were filled with an absorbent polymer. He said he had obtained thousands of results. (One of his annexed examples, however, was posted on the net a week after the priority date).

The skilled person could have learnt more about sandless sandbags from the fact that they were on the market in November 2009.

Gravitas’s evidence, supported by exhibited websites from 2008, was that EDS had marketed their ‘Floodsax’ products, barrage units manufactured using absorbent pads made according to the method claimed in the Patent, since that year. Synergy’s evidence was that they had manufactured the ‘Floodsax’ products since about 2007. (If correct, this manufacture and sale was a prior use of the claimed invention but I was not called upon to decide that).

In cross-examination Professor Penning-Rowsell said he thought that by 2009 the idea of sandless sandbags using absorbent polymer would have formed part of the skilled person’s common general knowledge. He accepted, though, that he found the distinction between what was known and what was the common general knowledge of the skilled person difficult. I think this was an honest and understandable concession. In his witness statement he said that the meaning of common general knowledge had been explained to him and I have no doubt it had. Yet it can occasionally be a slippery concept even to those who deal with it on a daily basis and I think it did Professor Penning-Rowsell credit that he qualified his evidence in this way. In any event, it is not for an expert witness to say definitively what was and was not part of the common general knowledge. He can give a view, provided he also sets out his understanding of what that means. But the primary job of the expert is to explain what knowledge was published at the relevant date, how and the degree to which it was disseminated to those in the relevant field. From that the court will draw conclusions about the state of the common general knowledge.

I think it is likely that by the start of 2009 the skilled person would have been aware that barrage units could be made by filling a bag or sack with absorbent polymer and I so find. He may well have heard of the ‘Floodsax’ product and if so, as a person interested in how barrage units can be made, would have known that the absorbent polymer is mixed with fibrous material and contained within pads which are then placed into the outer bags or sacks. Put another way, he would have learned that Floodsax are made using the absorbent pads with which he is deemed familiar. But I don’t think the skilled person’s knowledge of ‘Floodsax’ is essential to the defendant’s case. He is assumed to know already how to make the absorbent pads. He would know that they contain absorbent polymer. Once he also became aware that absorbent polymer could be used as a filler to make a barrage unit, in my view it would be obvious to use the absorbent pads as a filler. Counsel for EDS submitted that the disclosures relied on by Professor Penning-Rowsell taught away from the invention claimed because they did not disclose absorbent polymer with fibre. I reject that. The contents of the absorbent pads known to the skilled person would be about half absorbent polymer. There was nothing in the evidence to suggest that fibrous material would be regarded as undesirable as a filler in a barrage unit or anything worse than neutral. I take the view that it would have appeared to the skilled person that the absorbent pads would at the least be worth trying as fillers for a barrage unit, with a reasonable expectation of success given the disclosure of sandless sandbags.

It follows that there is no inventive step in claim 1 of the Patent.

EDS submitted that “arranging” in claim 9 means putting the pads in the bag or sack in a manner that would achieve uniform expansion. This would in particular be as shown in figures 5 and 6 of the Patent which illustrate the pads either laid end to end or packed in neat rows.

No reason was advanced by EDS as to why such a way of putting the absorbent pads in the bag or sack would not be at least one of the obvious ways of doing it. Professor Penning-Rowsell stated that it would be important and obvious to the skilled person to assemble the pads in the bag in a way that was not just a jumble because otherwise the pads would accumulate at one end of the bag and lessen the effectiveness of the barrage unit as a water block. I accept that evidence. There is no inventive step in claim 9.

In my judgment there is no inventive step in the methods of manufacture of barrage units as claimed in any of claims 1, 6 and 9 of the Patent.