Molylycke Health Care v Brightwake

Molnlycke Health Care AB (“Molnlycke”) and Brightwake Limited (“Brightwake”) are both manufacturers of wound dressings for use in hospitals. Molnlycke is the patentee of European Patent 0633757 (“the patent”) which concerns such a dressing. Molnlycke claimed that two products manufactured by Brightwake, both called Episil, infringed claim 6 of the patent. In a lengthy judgment HHJ Birss QC not only held that Episil in either form did not infringe the patent, but also held that the contested claims of the patent were invalid for obviousness over a particular piece of prior art referred to as Brassington. Brightwake relied on Brassington both in alleging that Brassington anticipated claim 6 and also that claim 6 was obvious. The novelty attack failed but the obvious attack succeeded. With the permission of the judge himself, Molnlycke appeal.

Since the launch of the appeal Molnlycke and Brightwake have settled their differences. Brightwake has not therefore participated in the appeal. However, the terms of settlement allowed Molnlycke to proceed with its appeal; it remains concerned to establish the validity of the patent and having it restored to the register. Notice was given to the Comptroller of Patents in accordance with Practice Direction 52 paragraph 21.3, but the Comptroller decided not to participate in the appeal either.

We have therefore only heard argument on behalf of Molnlycke, ably presented by Mr Iain Purvis QC and Dr Anna Edwards-Stuart. In addition, because the question whether Brightwake's products infringed the patent has now become academic, we have not heard argument on the question of infringement. I therefore express no view on whether the judge was right or wrong on that question. The patent is entitled:

The judge set out the technical background, which is not contentious. I reproduce the relevant parts of his summary here. A wound is a break in the skin. Dressings are applied to a wound in order to promote healing and prevent further injury. The dressings may have holes or perforations in order to allow for wound exudate to seep away from the wound. Gauze, generally produced from woven yarn of cotton, viscose or a mixture, has been widely used as a wound dressing. However, as the skin surface cells grow across the healing wound the tissue growth encapsulates the gauze. Removing the gauze then causes severe pain and damages the wound. One solution to this problem is to create a dressing with a hydrophobic layer nearest the skin. This solution dates back to the First World War when paraffin was used as a hydrophobic agent. These were known as tulle grasse dressings. Tulle grasse dressings remain in use. By the 1970s wound dressings consisting of clear polyurethane plastic films were available. These had an adhesive on the skin-contacting side. In these dressings the skin side is sticky and the other is not. These also remain in use today. Another kind of wound dressing from the 1970s and still in use today consists of a perforated plastic film and an absorbent pad. These are multilayered dressings. The perforated film is in contact with the wound and the absorbent pad absorbs any exudate. A film may be attached to one side of the pad only or may completely surround it. The judge described other forms of dressing in use, but these played no part in the reasoning so I omit them.

The judge set out the relevant parts of the patent. It starts with a general description of the invention:

“The present invention relates to a method and to an arrangement of apparatus for manufacturing wound dressings of the kind which comprise a perforated carrier material and a layer of hydrophobic silicone gel which lies against the wound or sore when the dressing is worn. The invention also relates to a wound dressing manufactured in accordance with the inventive method.”

Despite the last quoted sentence, the judge held -- and it is not disputed -- that the product claimed in claim 6 is not limited to a product made by the patented process. The patent continues by referring to some of the prior art. Of particular importance is reference to European Patent Application European Patent Office 0251810A2: this is Brassington. The patent says in terms that Brassington discloses the features of the preamble of claims 1, 4 and 6. Thus the patent acknowledges that Brassington discloses 1) a wound dressing comprising, 2) a perforated carrier material, and 3) a layer of hydrophobic silicone gel which lies against the wound surface when the dressing is worn. The patent continues by describing the method of manufacture. Since we are not directly concerned with the method I can deal with this briefly.

Essentially the method involves applying uncured silicone mixture to the upper surface of a perforated carrier material and blowing cold air on the underside in order to blow the mixture away from the perforations and prevent clogging of the holes. At the same time the cold air ensures that the silicone does not begin to cure before it has spread over the carrier. The air flow would prevent the silicone mixture running through the holes. Heat is used to cure the silicone mixture.

As noted, the first of the characterising integers is that the carrier material is impervious to air and fluid, or only slightly impermeable to air and fluid in the parts of it lying between the perforations. The patent explains why this is important:

“In order to prevent the silicone mixture from being blown from the carrier material, it is essential that the carrier material is impervious to air, or at least so impervious that essentially all air will flow through the perforations. However, material which permits air to diffuse therethrough can be used beneficially when practicing the invention. The carrier material shall also be impervious to fluid, or at least have a fluid-permeability which is so low that the thick-viscous fluid, i.e. the silicone mixture prior to curing, is unable to run therethrough.”

As the judge commented in paragraph 38:

“Thus the carrier material needs to be sufficiently impervious to air such that when the air is being blown on the underside, the air flow will be through the perforations rather than through the carrier material itself. However the carrier material can be “breathable” – i.e. allow air to diffuse through to the wound when in use. The material also has to be sufficiently impermeable to fluid that the uncured or partially cured silicone mixture does not just run through.”

The patent then gives examples of a number of suitable carrier materials. They are relatively soft plastic sheets and examples include polyurethane film and silicone film; however, the patent also envisages the use of a two ply carrier. The second of the characterising integers was that the carrier material is coated with silicone gel on only one side. Clearly, in the light of what has gone before, this will be the wound side. The patent then deals with the side of the carrier material that is not coated with silicone gel. It says:

“That side of the carrier material which is not coated with silicone gel will preferably have a uniform and smooth surface, so as to have low adherence to any dried wound fluid which may have exuded through the perforations as the dressing is worn. This is particularly important when the dressing is used together with an overlying absorbent body or pad, since it must be possible to remove the absorbent body without the dressing being disturbed as a result of wound fluid that has dried on the absorbent body adhering to the carrier material and entraining the material in the initial stages of removing the absorbent body.”

The judge commented in paragraph 43:

“One of the points being made here is that because the outside of the carrier material is not coated with silicone gel, it needs to have a uniform and smooth surface in order to give it a low adherence to exudate coming through the perforations so that an absorbent pad placed on top can be readily removed.”

Having described the various methods of manufacture, the patent, as the judge put it, takes stock. It says:

The patent then discusses the properties of the silicone gel to be used in the dressings, which the judge summarises in paragraph 50 of the judgment. The judge identified four issues of construction of the patent that divided the parties at trial. I do not understand Mr Purvis to dispute the judge's construction. His first complaint was that the judge wrongly assessed Brightwake's product, but, since Molnlycke and Brightwake have settled the infringement dispute, those complaints are no longer relevant. However, I should briefly mention the judge's conclusion on one of the disputed integers.

The issue in question was the meaning of silicone gel. Brightwake argued that the silicone gel referred to in the patent was a tacky material and that the skilled reader would construe the claim in that way. Molnlycke argued that tackiness should not be read into the claim. The judge said that, although tackiness is a significant characteristic in distinguishing between a gel and an elastomer, it is not the only one. He described the technical meaning of silicone gel in paragraph 115 of his judgment. However, he went on to hold that, although the patent was drafted on the basis that the silicone gel was likely to be sticky, the claim did not actually mention that characteristic. Having considered the arguments on both sides, the judge concluded in paragraph 121:

Although initially I had some doubt about the meaning of this part of the judge's judgment, having heard Mr Purvis I am satisfied that by "the material itself" the judge meant a silicone gel in the technical sense that he described in paragraph 115 of his judgment as opposed to, for example, a silicone elastomer or rubber.

The validity of the patent was, as I have said, attacked on a number of grounds. One of those grounds was that it had been anticipated by Brassington and hence that the claimed invention was not new. Another was that the claim invention was obvious over Brassington. Thus the judge began his consideration of validity by describing the teaching of Brassington. Brassington was a European patent application published by Johnson & Johnson on 7 January 1988. The abstract describes the invention as follows:

“A wound dressing comprises, in one embodiment, a layer of apertured material, such as a cotton gauze, coated with a tacky silicone gel or a non-tacky silicone elastomer. In an alternative embodiment, the dressing has a tacky silicone gel on one surface and a non-tacky silicone elastomer on the other surface. The gel and elastomer may be formed by crosslinking a mixture of a vinyl-substituted poly (dimethylsiloxane) and a hydride-containing poly (dimethylsiloxane).”

It was not disputed that Brassington disclosed a wound dressing comprising a perforated carrier material and a layer of hydrophobic silicone gel which lies against the wound surface when the dressing is worn. This was the preamble to claim 6 of the patent in suit, and the patent had expressly stated that this was disclosed in Brassington. Brassington also described three embodiments. The judge summarised them in paragraph 221 of his judgment as follows:

Although the specific embodiments disclosed by Brassington all use gauze as a carrier layer, the specification had referred to the possibility of using plastics material as the carrier. It said:

As Mr Purvis pointed out, each of the embodiments described by Brassington comprise cotton gauze coated with silicon on both sides. The judge agreed in paragraph 232 that:

He added that the skilled reader reading Brassington without hindsight would not have been taught to leave one side of the dressing uncoated with silicone. However, he went on to consider what Brassington disclosed about dressings coated on both sides with silicone but each form of silicone having different properties. He said in paragraph 235:

This conclusion raised the question whether the non-tacky silicone coating could be described as a gel within the meaning of claim 6 of the patent. The judge held that Brassington was not concerned with the niceties of whether a particular form of silicone coating was a gel rather than an elastomer or a rubber. Rather, what Brassington was concerned with was whether the coating was tacky or not. The judge referred to the decision of this court in Dr Reddy's Laboratories v Eli Lilly [2009], EWCA Civ 1362 [2010] RPC 9 as establishing that a generalised description does not disclose a specific matter falling within it, and that what is required for disclosure is an individualised description. He said in paragraph 240:

“The thrust of this aspect of Brassington’s disclosure is to employ tacky silicone gels on one side and non-tacky materials on the other side. In my judgment Brassington can be regarded as disclosing a continuum of non-tacky silicones ranging from gels to more cross-linked silicone elastomers, which Brassington calls silicone rubbers and which are not gels on any view. Although the skilled person would not be aware of claim 6 of course, in fact the tacky gel on the wound contact side would be a “silicone gel” in claim 6 while a more cross-linked non-tacky silicone rubber would not be a silicone gel as referred to in claim 6. However bearing in mind Dr Reddy's v Eli Lilly (above) in my judgment an individualised disclosure of a combination of plastic film as the substrate, tacky silicone gel on the wound side and non-tacky silicone rubber (and not gel) on the other side is not in Brassington.”

His ultimate conclusion was that Brassington disclosed a wound dressing which he described as follows:

“In summary, Brassington discloses a wound dressing with features (i), (ii) and (iii) of claim 6. The relevant wound dressing is one with an apertured plastics film carrier material, tacky silicone gel on the wound contacting side and non-tacky silicone on the other. Features (iv) and (v) are not disclosed in combination with the others and thus claim 6 is novel.”

Thus the judge concluded that Brassington did not anticipate the patent.

As I have said, the key integers of the patent for present purposes are that the carrier material is substantially impervious to air and fluid and that the carrier material is coated with silicone gel on one side only. The remaining question for the judge was whether a dressing with those characteristics was obvious over Brassington. He correctly directed himself in accordance with the judgement of Jacob LJ in
Pozzoli Spa v BDMO SA & Anr [2007] EWCA Civ 588, [2007] FSR 37:

“(1)

(a) Identify the notional “person skilled in the art”;

(b)

Identify the relevant common general knowledge of that person;

(2)

Identify the inventive concept of the claim in question or if that cannot readily be done, construe it;

(3)

Identify what, if any, differences exist between the matter cited as forming part of the “state of the art” and the inventive concept of the claim or the claim as construed;

(4)

Viewed without any knowledge of the alleged invention as claimed, do those differences constitute steps which would have been obvious to the person skilled in the art or do they require any degree of invention?”

The judge also correctly identified the differences between Brassington and the invention claimed by the patent as being integers 4 and 5; that is, that the carrier material is impervious to air and fluid, or only slightly impermeable to air and fluid, and that the carrier material is coated with silicone gel on only one side. Thus the question for the judge was whether it would have been obvious to have made a dressing whose carrier layer was an apertured plastics film, or similar, quoted with silicone gel on one side only.

The case of obviousness advanced by Brightwake and supported by its expert witnesses was that it was obvious to coat one side with a plastic film of silicone gel and leave the other side uncoated with anything. The judge rejected that case. He said in paragraph 322:

“Starting from Brassington and taking the step of coating with silicone on only one side is the kind of step which looks obvious in retrospect. However in my judgment it was not obvious, viewed without hindsight. It is not contemplated in the document itself and does not form part of the common general knowledge. The silicone coated wound dressing in the common general knowledge in 1992 (Silicone N-A) was coated on both sides. Coating on one side only is a simple step to take but that is entirely different from saying it was an obvious step to take.”

How, then, did the judge conclude that the invention claimed by the patent was obvious over Brassington? In fact, he dealt with this in the preceding section of his judgment. The judge began by discussing the use of plastics in wound dressings. He said in paragraph 293:

“Apertured plastics films were used in wound dressings already and formed part of the common general knowledge (e.g. Melolin). Plastics films without apertures were also used in wound dressings already as part of the common general knowledge (e.g. OPSITE). Brassington expressly mentioned dressings with plastic wound contacting layers at col 2 line 58. It is perfectly true that examples 1 to 3 use cotton fabric/gauze, and gauze is mentioned elsewhere too but the skilled reader would see the relevant part of the document as a clear teaching about the kind of materials which can be used as the substrate for the wound dressing described. It would be understood to be equally applicable to all of the three arrangements of silicone described in Brassington – tacky silicone gel on both sides, non-tacky silicone on both sides, and tacky/non tacky on opposite sides.”

Thus, he reasoned, the skilled reader would not have regarded Brassington's reference to apertured plastics films as mere speculation. From the foundation that apertured plastics films were known in the art as suitable for wound dressings, the judge proceeded to reason that the use of tacky silicone gel on the wound side of the dressing was disclosed by Brassington. He then said in paragraph 297:

“What kind of silicone would be used on the outside of the dressing? Brassington expressly gives the skilled reader a solid motivation to coat only the wound facing side with tacky silicone gel and put non-tacky silicone on the outside (col 6 lines 2-7).”

He added that a non-tacky silicone gel could have been silicone elastomer rubber rather than a gel. If one side of the dressing whose carrier layer was apertured plastics film had been coated with silicone gel and the other with a non-tacky silicone elastomer rubber, that would have been a product falling within the claim.

The key point, in my judgment, is the judge's statement that Brassington gave the reader a solid motivation to coat only the wound-facing side with tacky silicone gel and put non tacky silicone on the outside. This was an important building block in his ultimate decision. However, as Mr Purvis pointed out, the specific passage in Brassington to which the judge referred is immediately followed by describing a carrier material made of gauze. In my judgment, read in context the passage does not itself provide a solid motivation of the coating a plastics film with non-tacky silicone on the non-wound side. The judge said in paragraphs 298 and 299:

“In my judgment employing a silicone rubber as the non-tacky silicone in the tacky/non-tacky dressing would be entirely obvious. It is really no more than putting the relevant part of Brassington into practice. Such a silicone would not be a silicone gel within claim 6. I do not doubt that another obvious way forward over Brassington would be to use a non-tacky silicone gel, after all Brassington says as much as well. However that does not detract from the obviousness of employing a silicone rubber for the non-tacky component.

Accordingly in my judgment it would be obvious for a skilled team to propose making a wound dressing with tacky silicone gel on the wound side, a different non-tacky silicone on the outer face which would not be a silicone gel and a carrier material made of an apertured plastic film like polyurethane. This proposed product would satisfy claim 6. This is akin to a finding that such a product would be “obvious to try” in the sense of being obvious to try to make and so two further factors need to be considered. First would there be sufficient doubt that such a product could be made to put off a skilled team from even trying and secondly, even if they thought it was worth making, would the skilled team in fact succeed without invention?”

Thus what the judge was postulating was a plastics film coated with silicon on both sides; one side tacky, the other not. One property of the plastics film, one might suppose, would be that, absent the coating, it would not itself have been tacky on either side. Why then would the non-inventive skilled person, unaware of the patent, bother to coat the non-wound side with non-tacky silicone? It is at this point that Mr Purvis refers to the evidence of Professor Richard White given in support of Brightwake's case.

Professor White's evidence in paragraph 69 and following of his report was as follows:

It would have been pointless, because the plastics film would not itself have been likely to catch on clothing or bed linen. Thus the course of action that the judge held to be obvious was one that Brightwake's own expert had said was “wasteful and pointless”. In my judgment, this evidence fatally undermines the judge's finding that Brassington gave the skilled reader a solid motivation to coat the non-wound side of a plastic film carrier with non-tacky silicone. Mr Purvis says that this evidence played no part in the trial; but he says the reason it played no part at trial was precisely because the course of action that the judge eventually held to be obvious was not considered by the experts to be an obvious implementation of Brassington.

The granted patent is prima facie valid; thus the burden of proving that the claimed invention is obvious lies on the person attacking the patent. Whether a claimed invention is obvious is a multi-factorial question of judgment. An appellate court must be very cautious about reversing a finding of the trial judge. In the case of a specialist patent judge an appellate court must be all the more cautious. I remind myself of the warning given by Lord Hoffman in Biogen Inc v Medeva Plc [1997] RPC 1:

“It is because specific findings of fact, even by the most meticulous judge, are inherently an incomplete statement of the impression which was made upon him by the primary evidence. His expressed findings are always surrounded by a penumbra of imprecision as to emphasis, relative weight, minor qualification and nuance (as Renan said, la vérité est dans une nuance), of which time and language do not permit exact expression, but which may play an important part in the judge's overall evaluation. It would in my view be wrong to treat Benmax as authorising or requiring an appellate court to undertake a de novo evaluation of the facts in all cases in which no question of the credibility of witnesses is involved. Where the application of a legal standard such as negligence or obviousness involves no question of principle but is simply a matter of degree, an appellate court should be very cautious in differing from the judge's evaluation.”

One of the important points that Lord Hoffman made is that a finding of obviousness is a finding of fact. The finding of fact must be based on evidence. In Mölnlycke AB and Another vs Procter & Gamble Limited Number 5 [1994] RPC 49 Sir Donald Nicholls V-C said that when considering obviousness:

Aldous LJ followed that general approach in Panduit Corporation v Band-It Co Ltd [2002] EWCA Civ 465, [2003] FSR 8. The danger of a judge pursuing technical routes of his own without supporting expert evidence was also stressed by this court in Security
Ltd v Siemens Schweiz AG [2008] EWCA Civ 1161, [2009] RPC3. In the Panduit case, the trial judge had rejected the evidence of the experts but had nevertheless gone on to find that an invention was obvious. That has parallels with the present case in which the judge rejected the main thrust of Brightwake's case on obviousness. But there is more than a parallel, because in the present case Brightwake's' own expert had disavowed the so-called obvious route to the invention that the judge preferred. The judge's finding was not just a finding made without supporting expert evidence; it was a finding made contrary to the expert evidence. It is well established that the mind-set of the skilled addressee at the priority date is part of the state of the art. Professor White's evidence stood proxy for the skilled addressee. His evidence, which we are told was the only evidence on the topic, was that the skilled addressee would think that coating the non-wound side of a plastic film carrier was wasteful and pointless. Thus he would not have had any motivation to try to make the product that the judge described. Mr Purvis also submitted that there were technical difficulties in making the product, but I do not think that they add much, if anything, to his primary submission.

Mr Purvis submits that it was not open to the judge to make the finding that he did: it was not supported by the evidence; it was in fact contrary to the evidence, and it was unfair to Molylycke because it was not the argument they had come to meet at trial. I accept that submission. In my judgment, the judge did make an error of principle in postulating a non-inventive route to the invention that was contrary to the only expert evidence on the subject. In so finding, he did not take into account a highly relevant factor, namely the mindset of the skilled addressee as represented by Professor White's evidence, which showed that the skilled addressee would have had no motivation to embark upon the course that the judge proposed. I would therefore allow the appeal on that point.

I agree.

I also agree.