Wake Forest University Health Sciences & Ors v Smith & Nephew Plc & Anor [2009] EWCA Civ 848

[2009] EWCA Civ 848

Case No A3/2009/0931 & A3 2009/1227

IN THE SUPREME COURT OF JUDICATURE

COURT OF APPEAL (CIVIL DIVISION)

ON APPEAL FROM THE HIGH COURT OF JUSTICE

CHANCERY DIVISION

PATENTS COURT

Mr Roger Wyand QC

[2009] EWCH 908

Venue Royal Courts of Justice, Strand, London, WC2A 2LL

Date 31/07/2009

Before

LORD JUSTICE WARD

LORD JUSTICE JACOB

MR JUSTICE WARREN

Between

(1) WAKE FOREST UNIVERSITY HEALTH SCIENCESClaimants/

(2) KCI MEDICAL LIMITEDRespondents

(3) KCI MEDICAL RESOURCES (a company incorporated under the laws of Ireland)Respondent

(Transcript of the Handed Down Judgment of

WordWave International Limited

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James Mellor QC and Andrew Lykiardopolos (instructed by Messrs Bristows) for Appellants

Daniel Alexander QC and James Abrahams (instructed by Messrs Olswang) for Respondents

Hearing Hearing dates : 9th July 2009 and 14th July 2009

Judgment

Mr Justice Warren (giving the first Judgment at the invitation of Lord Justice Ward)

Introduction

[1]The appeal and cross-appeal in this case relate to Patent EP 0 620 720 (“the Patent”). The Patent concerns a medical device shortly described as “Apparatus for treating tissue damage”. The invention (see paragraph [0001]) relates “generally to wound healing, and more specifically is directed to apparatus for treating wounds that are unlikely to heal completely under conventional methods.”

[2]The proprietor of the Patent is the first Claimant/Appellant (“Wake Forest”). The second and third Claimants/Appellants (together “KCI”) are between them exclusive licensees and carry out the commercial exploitation of the invention.

[3]The Judge, Mr Roger Wyand QC sitting as a Deputy Judge in the Patents Court held that certain claims, including the main claim, Claim 1, were anticipated. He rejected the contention of the Defendants/Respondents (together “S&N”) that other claims, in particular Claims 4, 16 and 19, were obvious.

[4]S&N appeal against those findings concerning obviousness. Wake Forest and KCI cross-appeal against the findings of invalidity in relation to Claim 1 and various other claims. It is only the cross-appeal in relation to Claim 1 on the grounds of anticipation which has been pursued in this Court.

Background

[5]The prior art relied on by S&N is a paper written in Russian by a Russian doctor, NA Bagautdinov ( “Bagautdinov”) which I shall consider in detail later. It dates from 1986. It refers to a number of earlier papers, including one dating from 1984, by SV Lohvitskii and AA Bilkevich: the title of that earlier paper is “External vacuum aspiration in the treatment of purulent disorders of the soft tissues”. This paper is not part of the cited prior art but it provides some interesting history. After a very brief description of external vacuum aspiration, we find this:

“The external vacuum aspiration method consists in the placement of a vacuum instrument outside the wound cavity. It was first proven and used by N.I. Pirogov. [see http://en.wikipedia.org/wiki/Nikolay_Ivanovich_Pirogov for further information]. In his “Report on the Journey to the Caucasus” (1849), he wrote that to create the efflux and removal of foreign bodies from gunshot wounds, “….in many cases, I replaced incisions to advantage by the attachment of a cupping glass at the entry and exit holes.”

It was not until the end of the 19th century that A. Bier and R. Klapp used the already long forgotten glass as one of the options for creating congestive hyperemia in an inflammatory focus for the purpose of activating the body’s defensive powers to fight infection. The method of Bier and Klapp was widely used until 1920’s – 1930’s, and many surgeons have remarked that it implements the classic principal of purulent surgery, the removal of pus from a wound. Yet, during the period in which antibiotic therapy blossomed, the method was forgotten and, in the opinion of S. T. Pavlov (1957), began to represent only historical interest.”

[6]In the West, development of the technique did not occur until the late 1980s. At least, there is no evidence of any research or development. Indeed, Dr Orgill, the expert for Wake Forest and KCI, has exhibited to his report an article, co-authored by himself and Dr Hemling, which was published in 1988. It was entitled “Current concepts and approaches to wound healing”; it does not mention the technique but, under the heading New Advances, mentions a number of entirely different technologies - Growth Factors, Human Growth Hormone and Skin Substitutes.

[7]Before turning to the Patent and Bagautdinov, I note that the skilled team would include, as is common ground, a surgeon experienced in the treatment of wounds and a wounds nurse. The team, working on wound treatment, would be entirely familiar with a variety of wounds and with common techniques and equipment to be found in hospitals where treatment takes place. No dispute exists about the state of the common general knowledge, the relevant details of which I will cover later.

[8]No dispute exists, either, about the correct approach to obviousness. Although it is not compulsory, it is usually a helpful approach – and certainly so in the present case – to apply the Windsurfing test as re-stated by Jacob LJ in Pozzoli v BDMO

[2007] FSR 37

. The test is, of course, now well known but it is worth setting out again: (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.

[9]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 application of steps (1) to (3) does no more than place the court in the correct frame to assess obviousness under step (4). It does not itself provide a test for obviousness. Nor does it provide any gloss on the single statutory question. The judge did not refer to Pozzoli. He did not address the steps set out in the test as set out there. As will be seen I think this led him into error.

[10]The authorities are full of examples of different glosses which the courts have, in a wide variety of circumstances, placed on the statutory test namely that an invention shall be taken as involving an inventive step if it is not obvious to a person skilled in the art. The correct approach is stated by Kitchin J in Generics v Lundbeck

[2007] RPC 32

at 72 (cited with approval by Lord Hoffmann in Conor Medsystems Incorporated v Angiotec Pharmaceuticals Incorporated

[2008] UKHL 49

[2008] RPC 28

) when he was considering how a number of different factors should be taken into account:

"The question of obviousness must be considered on the facts of each case. The court must consider the weight to be attached to any particular factor in the light of all the relevant circumstances. These may include such matters as the motive to find a solution to the problem the patent addresses, the number and extent of the possible avenues of research, the effort involved in pursuing them and the expectation of success."

[11]I have well in mind that S&N are asking us to overturn the Judge’s findings on obviousness. Mr Alexander reminds us of the role of the appellate court in a case of obviousness and of the decision in Biogen Inc. v Medeva Plc

[1997] RPC 1

, in particular the part of Lord Hoffmann’s speech at 45 where he said:

“The need for appellate caution in reversing the judge's evaluation of the facts is based upon much more solid grounds than professional courtesy. 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.”

[12]Those observations are directed not at the facts as found by a judge but to his evaluation of them in the context of the ultimate question of obviousness. If a judge has adopted the wrong approach to obviousness – for instance taking a mistaken view as what is disclosed by the prior art or what the difference between the prior art and the claim under attack is – then of course the appellate court will have to form its own evaluation on the basis of the facts as found by the judge or which appear clearly from the documents or other evidence without having been expressly mentioned in the judgment.

The Patent

[13]The Patent has a priority date of 14 November 1991. I have set out paragraph [0001] already. The background of the invention is set out in paragraphs [0002] to [0005]. So far as material to the present appeal, they read as follows:

“[0002] The treatment of open wounds that are too large to spontaneously close has been a troublesome area for many years. Wound closure requires that epithelial and subcutaneous tissue adjacent to the wound migrate toward and eventually close the wound. Some wounds are sufficiently large or infected that they are unable to close spontaneously. In such instances, a zone of stasis, an area in which localized swelling of tissues restricts the flow of blood to these tissues, forms near the surface of the wound. Without sufficient blood flow, the wound is unable to successfully fight bacterial infection and accordingly is unable to close spontaneously. [0003] The most common techniques for closure of open wounds has long been the use of sutures or staples….[Suturing and stapling] has a major drawback: the tensile force required to achieve closure with sutures or staples causes very high localized stresses at the suture insertion points, resulting in the rupture of the tissue at these points. Substantial rupture will eventually cause dehiscence [ie tearing] in some wounds, which results in additional tissue loss……Examples of such wounds include large, deep, open wounds, pressure sores resulting from prolonged pressure, ulcers resulting from chronic osteomyelitis, and partial thickness burns that subsequently develop into full thickness burns. [0004] To date, there has been no consistently satisfactory method for treating such wounds. What is needed is a method of closing the wound without the localized stresses that accompany suturing while at the same time treating any infection present in the wound along with a simple apparatus to carry out the method. Such a method and apparatus would reduce hospitalization and increase the probability of wound closure.”

[14]As the Judge said, it can be seen from this that the invention, if it be such, resides in the method of treating a wound. However, since it is not possible to obtain a patent for a method of treating the human body, it is claimed in the form of apparatus which is suitable for carrying out the method of treatment. The “Summary of the Invention” is:

“[0007] The invention provides an apparatus for facilitating the healing of a wound according to claim 1. The embodiment of the invention comprises an open-cell polymer foam section configured to overlie a wound, and a flexible tube having an inlet end and an outlet end, said inlet end being inserted into said open cell polymer foam section. A flexible polymer sheet may overlie the foam section and tubing and be configured to be adhered to the skin surrounding the wound.”

[15]Further details of the apparatus and the method are set out under the “Detailed Description of the Invention”:

“[0010] The present invention relates to an apparatus for treating tissue damage according to claim 1. Wound closure requires that epithelial and subcutaneous tissue migrate from the wound border toward the wound. The use of negative pressure provides tension on this border tissue that causes accelerated tissue migration. It has been observed that the use of the apparatus also causes within the wound increased formation of granulation tissue, a matrix of collagen, fibronectin, and hyaluronic acid carrying macrophages, fibroblasts, and neovasculature that aids in healing. [0012] The invention can be practiced with the application of substantially continuous negative pressure, where the pressure is relieved only to change the dressing on the wound, or it can be practiced with the use of a cyclic application of pressure in alternate periods of application and non-application. The ratio of duration of application period to non-application period can be as low as 1:10 or as high as 10:1, but is most preferably 1:1. A preferred pattern is 5 minutes of pressure application followed by 5 minutes of relief. [0013] The invention is practiced using a negative pressure ranging from 1.01 and 100.3 kPa (0.01 to 0.99 atmospheres) and more preferably practiced using a negative pressure ranging between 50.7 and 81.1 kPa (0.5 to 0.8 atmospheres). The time period for use of the method on a wound is preferably at least 12 hours, but can be, for example, 1 day, 2 days, 5 days, 7 days, 14 days, 30 days, or even longer. There is no upper limit beyond which use of the method is no longer beneficial; the method increases the rate of closure up to the time the wound actually closes. [0014] Open wounds are almost always contaminated with harmful bacteria. Generally, a bacterial density of 15 5 bacterial organisms per gram of tissue is regarded as infected……We have observed that application of negative pressure to a wound will reduce the bacterial density of the wound; it is believed that this effect is due to either the bacteria’s incompatibility with a negative pressure environment or the increased blood flow to the sound area, as blood brings with it cells and enzymes to destroy the bacteria.”

[16]The Judge did not refer to paragraphs [0019] to [0023] of the Patent. They describe the apparatus rather than the method and so far as relevant read as follows:

“[0019] Apparatus according to the present invention for facilitating the healing of wounds comprises vacuum means such as a pump for creating a negative pressure on the area of skin surrounding the wound, sealing means such as an adhesive sheet operatively associated with the vacuum means for maintaining negative pressure on the wound by contacting the skin surrounding the wound, and screen means such as an open-cell foam section located with the sealing and for preventing the overgrowth of tissue in the wound area. [0020] …….The screen means comprises an open-cell polymer foam….. [0021] Possible sealing means include……a flexible polymer sheet overlying the screen means and the vacuum means and attached to the skin through an adhesive applied to the sheet surface facing the skin…… [0022] Suitable vacuum means includes any suction pump capable of providing at least 689.5 Pa (0.1 psi) suction to the wound…. The pump can be any ordinary suction pump suitable for medical purposes that is capable of providing the necessary suction… [0023] A preferred embodiment of the invention shown in Figure 1 [see paragraph 40 below] comprises a substantially flat section of open cell polyester foam…….., a flexible hollow tube…inserted into the open cell foam….and joined thereto with an adhesive and extending to attach at its opposite end to a Cast Vacuum Pump…, and an Ioban adhesive sheet…….”

[17]The claims relevant to this appeal, Claims 1, 4, 16 and 19, are as follows:

“1. An apparatus for facilitating the healing of a wound, comprising vacuum means for creating a negative pressure on the area of the skin including and surrounding the wound and sealing means operatively associated with said vacuum means for maintaining said negative pressure on said wound by contacting the skin surrounding said wound, characterised in that said negative pressure is between about 1.01 and 100.3 kPa (0.01 and 0.99 atmospheres) and in that said apparatus comprises screen means for positioning at the wound within the sealing means for preventing overgrowth of tissue at the wound in which said screen means comprises an open-cell polymer foam. 4. An apparatus according to claim 1 in which said sealing means includes a flexible polymer sheet overlying said screen means, said polymer sheet having adhesive on at least a surface facing the wound to attach and seal said polymer sheet to said surrounding skin. 16. An apparatus according to any one of claims 1 to 14, in which said vacuum means operates cyclically to provide periods of application and non-application of suction. 19. The apparatus according to claim 16, wherein said vacuum means operates cyclically to provide periods of application and non-application of suction with the ratio of duration of application period to non-application period between about 1:10 and 10:1.”

[18]Claim 1, it can be seen, requires three components:(i) the vacuum (what the Patent refers to a negative pressure) means (in essence, a pump and connecting tube)

(ii) a sealing means (such as a film) and

(iii) a dressing referred to a screen-means, the claim being limited to screen-means made from an open-cell polymer foam.

Common general knowledge

[19]The Judge set out the relevant common general knowledge in paragraphs 16 to 24 of his judgment. Whether this was common ground or represent findings I do not know, but there is no challenge to what he says. Since all of it is of some relevance to how the skilled person would read the Patent and the prior art, I set out those paragraphs in full: 16 Common general knowledge in wound treatment at the relevant date included the following information. 17 The stages of wound healing in a clean wound are as follows:(a) haemostasis (stopping bleeding) and clot formation;

(b) inflammatory phase during which bacterial infection is reduced and dead tissue removed;

(d) remodelling phase when scar tissue forms and the skin barrier is restored. It was common ground that these stages are not clearly defined and overlap to varying degrees, depending upon the nature of the wound. Cleaning, dressing and leaving to heal naturally 18 In 1991, the main approach to getting a wound to heal was to clean and dress it. Where necessary, this involved surgical debridement (removal of dead tissue). The wound would then be left to heal naturally. Surgical wound debridement was used in conjunction with mechanical debridement with gauze. Gauze would adhere to necrotic tissue, thereby removing a small fraction of necrotic material with each dressing change. Dressings would be changed 1 to 4 times daily, often causing some degree of pain with each dressing change. A number of moist wound dressings were available in 1991, which included alginates and hydrocolloids. Enzymatic debridement agents such as collagenase and papain urea were also available but infrequently used. 19 Suction was another method used to evacuate pus and free floating dead material from wounds, particularly if they contained a lot of pus, followed by irrigation which was the mainstay of cleaning the wound. This technique is referred to as “irrigation and aspiration”. Sutures/staples 20 Wounds were also encouraged to close by mechanical means. Suturing or stapling of wounds were the most widely practiced techniques for closing surgical wounds in 1991. Occasionally these devices were used to close chronic wounds after surgical debridement. 21 However, to close a large wound requires high tensile forces on the skin at the wound edge. With sutures/staples, this large force is localized to a very small area where the sutures/staples are inserted into the skin. As a result, there is a risk that the sutures might tear the skin at the wound border when they are used to close large, open wounds. Not only does this not facilitate healing, it causes further tissue degradation, exacerbating the condition. A number of mechanical wound tension devices that could ratchet the wound closed had been and continued to be developed; however there has been little penetration of these devices into surgical practice primarily because of the destructive complications found at the wound edge. Materials used 22 Plastic films were used in surgery, particularly to protect the skin around an incision. These films tended to be self adhesive. 23 Polyurethane foam sponges were used as prep sponges to clean the area prior to surgery. 24 Vacuum pumps were used to remove fluids from wounds and incisions. By 1991 these were not in common use but there was often a wall socket providing a vacuum source.”

[20]I should comment on the last sentence of paragraph 21. Mr Mellor says that this is an understatement. He is right in that observation. Neither expert could think of a film which was not, at the priority date, adhesive. Dr Orgill was cross-examined about this and was able to think of only one commonly available film which he thought was non-adhesive but even this, it turned out, had adhesive along its edge. Dr Gordon’s unchallenged evidence was that common adhesive coated films in 1991 used in surgery were Tegaderm and Opsite. Dr Orgill agreed that adhesive films were “very well known to people working in wound management”. So far as concerns vacuum pumps, the uncontroverted evidence was that pumps were available at the priority date. One of these was the Gomco pump which had a constant and intermittent vacuum setting.

[21]The Judge’s summary reflects very much what was said by Dr Gordon, the expert for S&N. Mr Mellor took the court in more detail through the relevant passages of Dr Gordon’s report which I think were not contentious: at least, Mr Alexander made no comment in his submissions. Although it was helpful to have this detail, I do not think it necessary to set it out here other than to say a little about granulation (which is referred to by the Judge). This is the formation of granulation tissue, described by Dr Gordon as:

“a mixture of capillaries formed by angiogenesis and collagen and other molecules produced by fibroblasts and additionally some other cells such as lymphocytes and macrophages. The term granulation tissue derives from its moist, soft, granular appearance. Granulation tissue fills the sound before it covered with a new epidermal layer of skin…”

[22]The Patent refers to “overgrowth of tissue”. Wound overgrowth is a phenomenon where the granulation tissue crosses above the surface of the skin. The evidence was it does not happen very often, but it can happen. One of the benefits of using the process described in the Patent is that it prevents wound overgrowth. The solution is to apply pressure and that stops the process.

Bagautdinov

[23]Bagautdinov was published as part of the book “Current Problems in Modern Clinical Surgery: Interdepartmental Collection”, edited by V. Ye. Volkov et al (1986). As recorded by the Judge, the book was pleaded to have been made available for public inspection at four libraries in the then USSR. Initially the public availability of the book was denied by Wake Forest and KCI but shortly before trial they accepted for the purposes of these proceedings that it had been made available to the public before the priority date of the Patent.

[24]Bagautdinov was published in Russian. It is a short document running, in the translation before the court, to only 70 lines over 3 pages. It is structured, as the Judge observed, like a patent: it refers to the prior art, the problems associated with the prior art and then sets out the proposed solution. Since it is not possible to understand the teaching of Bagautdinov without the document at hand, I set it out in the Appendix to this judgment.

The teaching of Bagautdinov

[25]The extent of the teaching is important. For upon it depends the key difference between it and the teaching of the patent – Pozzoli step 3

[26]It was suggested from time to time on behalf of Wake Forest and KCI that Bagautdinov is concerned only with the inflammatory stage of wound healing but not with subsequent stages, in particular the proliferative stage. I do not think that that can be correct. First, as was part of the common general knowledge, the four phases of wound healing are not clearly defined; there is overlap. Secondly, and more importantly, a reading of Bagautdinov itself does not support that conclusion. Quite apart from the reference to the then existing treatments (which I will come to in a moment) the references in the final paragraph to the “dynamics of change” can only be a reference to granulation; and the reference in the Conclusion to “sealing” also implies granulation since sealing can only take place after granulation.

[27]In any case, that suggestion has as its foundation the proposition that, prior to Bagautdinov, the treatments of which Bagautdinov was a variant were concerned only with the inflammatory stage. But a look at Lokhvitskii & Bilkevich shows that that is not so. They say that aspiration “takes the place of pressure bandages, improves the trend of the wound process, and accelerates obliteration of the cavity”. And a table of treatment results contains columns with headings including “Wound cleanup; Appearance of granulations; Start of epithelialisation.”

[28]Bagautdinov identifies three shortcomings with the then-existing negative pressure methods:a. the periphery of the working part of the vacuum should correspond to the shape and dimensions of the skin defect of the wound;

b. the hermetic installation [sealing] of the vacuum device is either impossible or extremely difficult to attain in certain areas of the body; and

c. the use of gauze, rubber strips and tubes as drains does not ensure uniform vacuum treatment of the entire cavity (surface) of the wound.

[29]Bagautdinov then sets out to teach an apparatus and a method to address each of those problems so that(i) negative pressure is applied over the entire surface of the wound

(ii) a seal can be obtained wherever the wound is found, including difficult areas such as limbs and

(iii) uniform vacuum treatment of the entire wound cavity is achieved.

[30]The treatment method is set out:a. After initial surgical treatment of the purulent wound, polyurethane foam which has been adapted to the size and shape of the wound is placed on the surface (or in) the cavity of the wound as a drain.

b. The skin surrounding the wound is then smeared with sterile Vaseline, antiseptic or inert salve on an oil base and covered with a polyethylene film. Recognising that there might be difficulties with that approach in some areas of the body (eg forearm, shoulder, shin and thigh), it is taught that a polyethylene sleeve can be used which is attached with plaster to the skin.

c. Regardless of the method of sealing, a tube is then hermetically installed through a hole in the polyethylene film. The tube is connected to a vacuum pump through a collection vessel.

d. The pump is operated at a vacuum of 10-60 mmHg. The operation of the pump and the creation of the negative pressure makes the film enclose the wound strictly along its skin boundaries. Negative pressure is not applied to the surrounding skin but only to the wound. This is the solution to the first problem and to the second problem where it is necessary to attach a sleeve with plaster.

e. This apparatus results in the uniform vacuum treatment on the sides of the cavity walls only. That is the solution to the third problem. Achieving uniform vacuum treatment means that the negative pressure gets to the whole surface of the wound. The process also achieves elimination of exudate because of the porous structure of the drain. The use of an open cell foam ensured that result, as both experts agreed.

f. One of the methods taught in Bagautdinov is to apply the vacuum from 30 minutes to 2 hours depending on the degree of vacuum. After this period the polyethylene film is removed and is replaced with a gauze bandage.

g. The sessions are then repeated daily usually for around 3-4 days.

h. Bagautdinov also teaches that, for patients with extensive purulent foci with a large amount of purulent secretion, continuous aspiration treatment can be conducted. The period of continuous treatment is not specified. With this method, the wound is irrigated by the use of a Y-shaped tube. This is placed above the polyurethane (ie the foam)

[31]Bagautdinov explains the good suction effect of the foam and its efficacy as a drain – wound secretions absorbed after 24 hours exceeding by a factor of 10 the weight of the foam. It is explained that throughout the treatment the pH was checked as was the total protein content of exudate and the dynamics of the change in area and volume of the wound.

[32]The skilled reader would be particularly struck by the statement that 170 observations were made and in all cases the wounds healed without complications. The teaching is that the treatment inevitably obtained acceleration of the healing periods [ie including granulation] and rehabilitation of the patients. And the conclusion is that the new treatment – which must subsume both apparatus and treatment – “accelerates cleaning and sealing of purulent wounds and cavities”.

The teaching of the Patent

[33]Although I have set out relevant part of the Patent, a summary of the teaching is useful. As can be seen, paragraphs [0001] to [0004] deal with the field of the invention and the problems sought to be addressed. It is concerned with wounds too large to close spontaneously for example large, deep, open wounds, pressure sores, ulcers and partial thickness burns which subsequently develop into full thickness burns. The Patent therefore seeks to find a method of closing the wound without the localised stresses that accompany suturing while at the same time treating any infection present in the wound along with a simple apparatus to carry out such method (the Claims of the Patent, of course, being only apparatus claims and not process claims).

[34]The summary of the invention in paragraph [0007] is enlarged on in paragraphs [0010] and following.

[35]Paragraphs [0010] and [0011] set out some of the benefits of negative pressure which, it is said, provides tension on the border of the wound that causes accelerated tissue migration. Use of the claimed apparatus is said also to cause an increase in formation of granulation tissue, a matrix of collagen and other aids to healing. Paragraph [0012] explains that the invention can be practised with continuous or cyclical negative pressure, in the former case, pressure being relieved only to change the dressing. Paragraphs [0014] to [0015] teach that the apparatus is useful with infected wounds. Negative pressure is said to reduce the bacterial density in the wound.

[36]So far as concerns the apparatus, paragraphs [0019] to [0022] contain important teaching. Paragraph [0019] refers to the three components: vacuum means, sealing means and screen means. I consider these in turn.

The Vacuum means

[37]The vacuum means are at large although paragraph [0019] refers to a pump. This is, of course, a pump which can create a negative pressure. It will clearly have a flexible hose attached. Mr Mellor says that there is nothing special about this pump. Any suction pump will suffice provided (see paragraph [0022]) that it is capable of providing at least 689.5 Pa (0.1psi) suction to the wound. This is likely to cover many pumps commonly used in 1991. Indeed, the Patent itself teaches in paragraph [0022] that “The pump can be any ordinary suction pump suitable for medical purposes that is capable of providing the necessary suction”. The pump can function continuously or may operate cyclically.

The Screen means

[38]The screen means is the wound dressing and corresponds to the polymer cell foam in Bagautdinov. The teaching concerning the screen means allows for considerable flexibility. It is to be placed “over substantially the expanse of the wound to prevent its overgrowth”. The skilled person will, no doubt, understand what is meant by “overgrowth” as I have already explained it. The mechanism by which this beneficial result is obtained is not explained. However, what is said is that the construction of the screen means can be adapted to the circumstances as can be seen from a reading of paragraph [0020].

The Sealing means

[39]Different examples of sealing means are given in paragraph [0021]. I am concerned only with the example of a flexible polymer sheet overlying the screen means and the vacuum means (ie the tube) and attached to the skin through an adhesive applied to the sheet surface facing the skin. However, provided there is an appropriate sealing means, it does not need to be one of the types described in paragraph [0021] to make a seal.

[40]Relevant to the present appeal is the first preferred embodiment mentioned in paragraph [0023]. It comprises a substantially flat foam section which is “sufficiently large to cover the wound and thus prevent wound overgrowth”. It has a tube from the pump inserted into the foam. It uses the commercially available Ioban adhesive sheet as the sealing means which overlies the foam and tubing and is adhered to the skin surrounding the wound, thus forming a seal. This allows the creation of a vacuum when the pump is operated. It is depicted as follows:

[41]The figure shows how the film might look before the vacuum is applied. Once the pump is switched on, the film is sucked down and pushes the foam onto the wound.

Claim 1 - anticipation

[42]The Judge held that Claim 1 was anticipated by Bagautdinov. He identified the following components of the apparatus described in Bagautdinov:(1) a polyurethane foam, adapted in shape and size to fit on or in the wound;

(2) sterile Vaseline smeared on the surrounding skin;

(3) a covering of polyethylene film enclosing the wound strictly along its skin boundaries (with limbs this can be a polyethylene sleeve attached to the skin with plaster and with hands and feet it can be a polyethylene sack also attached by plaster);

(4) a tube hermetically installed through a hole in the polyethylene;

(5) a vacuum pump (with a collection vessel) capable of generating a vacuum of 10 to 60 mmHg.

[43]He then identified the integers of Claim 1 of the Patent:(a) vacuum means for creating a negative pressure of 0.01 to 0.99 atmospheres on the area of skin including and surrounding the wound;

(b) sealing means operatively associated with said vacuum means of maintaining said negative pressure on said wound by contacting the skin surrounding said wound;

(c) screen means comprising an open-cell polymer foam for positioning at the wound within the sealing means for preventing overgrowth of tissue at the wound.

[44]He regarded S&N’s case on anticipation as simple. Components (4) and (5) of Bagautdinov correspond to integer(a) of the claim, components (2) and (3) of Bagautdinov correspond to integer

(b) of the claim and component (1) of Bagautdinov corresponds to integer

[45]The Judge rejected the argument on behalf of Wake Forest and KCI that component(1) of Bagautdinov is not necessarily an open cell foam, regarding it as clear from Bagautdinov that he is trying to get uniform vacuum treatment, something which could only be achieved, as the experts agreed, by the use of an open cell foam. He also rejected the argument that components

(2) and

(3) of Bagautdinov do not constitute sealing means within the meaning of the claims. There is no appeal from those aspects of his decision. Accordingly, the teaching of Bagautdinov is to create a seal with a flexible film.

[46]However, Mr Alexander, in what must be one of the shorter submissions he has ever made, suggested that the Judge should have taken a rather less broad view of Claim 1 than he actually did, and should have held that it contemplated and only contemplated maintenance of negative pressure for a long time – in other words “maintaining” means “maintaining over a long time”. The point really came down to construing the Claim in the context of a purpose which was to maintain negative pressure for a long period. But even if it is correct to do that, it is not nearly enough to result in a construction under which only an apparatus suitable for maintaining pressure for a long period falls within the Claim. We reject this argument. Accordingly, we conclude that the Judge was correct to hold that Claim 1 was anticipated by Bagautdinov.

Obviousness: a general defence

[47]One of the defences raised to the obviousness attack (whether in relation to Claim 4 or any other claim) was the alleged risk, or perception of risk, of the Bagautdinov method. It was argued before the judge, an argument repeated before us, that Bagautdinov would not have been regarded as suitable and, indeed, would have been seen by Western doctors as contrary to good practice. The Judge dealt with this at paragraphs 31 and 32. He concluded that the 170 observations recorded by Bagautdinov would be enough to allay any initial fear about leaving a dressing in a wound in accordance with the teaching of Bagautdinov. Not only do I see no reason to doubt that conclusion, it is one which I would myself have reached.

Obviousness: Claim 4

[48]I turn to obviousness of claim 4. Pozzoli step 3 applied here asks this: what is the difference between Bagautdinov and claim 4? Physically, in terms of apparatus, it is the use of adhesive film instead of Vaseline and a film. There is no other difference so far as the apparatus is concerned. But the answer to the question whether making that variant to Bagautdinov was obvious will inevitably be influenced by whether the change in the method of treatment was obvious. What difference in treatment is there? The answer is none: for the reasons I have given Bagautdinov is not confined to pus removal but covers the healing process overall.

[49]So Pozzoli step 4 comes to this: Was it obvious to treat large wounds for healing purposes including the granulation and later stages to use adhesive film instead of Vaseline and a film? That is the question.

[50]It may be there is even less difference than this. For Bagautdinov contemplates for difficult to cover body parts, (hands, fingers and feet) the use of polythene sacks attached “to the skin by a similar method proximal to the wound.” That may imply or suggest the use of adhesive to fix the sacks. But I am prepared to assume the difference I have stated.

[51]Mr Alexander for Wake Forest submitted that there was a good reason for not making the change – that the use of adhesive film would be likely to cause pain upon removal of the dressing and that it is less removable than a film held down only by Vaseline.

[52]I think there is nothing in this point. After all it was already well known to use adhesive film on the skin. And besides the amount of pain or discomfort would clearly depend on how aggressive the adhesive was. Moreover even though some discomfort may be involved, the trade off (faster healing, no graft and the like) would be seen as well worthwhile. Finally, I observe that the Patent does not solve the pain problem, such as it is. I consider this point in more detail later.

[53]The Judge dealt with obviousness in relation to Claim 4 quite briefly. In paragraph 50 of his judgment he recorded Mr Alexander’s argument that the technique of Bagautdinov was so different from the method of the Patent that there is no room for obviousness and that the case was one of “anticipation or nothing”. The Judge expressed sympathy for that approach, saying this:

“One has to be careful in approaching obviousness not to ignore the teaching and purpose of Bagautdinov unless the prior art can be said to point clearly to possible modification of the apparatus.”

[54]In paragraph 51 the judge recorded Mr Mellor’s submission that the attack on Claim 4 was on the basis that it would be obvious to use an adhesive coated polymer film in place of the non-adhesive film used by Bagautdinov. This he said provided a good illustration of an “anticipation or nothing” argument. He then referred to Dr Gordon’s evidence that it was in fact difficult to obtain non-adhesive polymer film in hospitals in 1991 and therefore that it would have been obvious to use adhesive polymer film in its place. He said this:

“However, Bagautdinov teaches to remove the polymer film after each treatment and to replace it with a gauze dressing. Using Vaseline with no adhesive makes it easier and more comfortable to the patient when the dressing is to be replaced so regularly.”

[55]In paragraph 52, he recorded Dr Gordon’s evidence that he had constructed his own device for use in hospital; he had used off-the-shelf products – surgical sponges for the “screen means” and adhesive polymer sheet which is used in surgical procedures. The Judge perceived a problem with this evidence: Dr Gordon was aware of KCI’s product but was not allowed to purchase it by his hospital authority on the ground of expense and was therefore seeking to replicate the product with what he had available. The Judge saw this as “a classic case of the application of hindsight to the problem”. This would not give any indication as to what the notional skilled addressee working from Bagautdinov and in ignorance of the Patent would have done.

[56]The Judge concluded in paragraph 53 that the skilled addressee would have no reason to modify Bagautdinov by using adhesive polymer film and that “this would actually be contrary to the teaching of Bagautdinov who uses an easily removable polymer film”. Accordingly, he decided that Claim 4 was not obvious.

[57]Mr Mellor has a number of criticisms of this reasoning. According to him, not only did the Judge go wrong in what he actually said, but his reasoning fails to take account of certain factors which would have led him inevitably to the opposite conclusion. Mr Alexander says that the Judge was correct in his approach and reasoning. Indeed, he submits that the evidence of Dr Orgill about how the skilled person would have reacted and his answer to the ultimate question (ie that Claim 4 was not obvious) was not controverted and that it is not open to this Court to reach a contrary conclusion from not only Dr Orgill but also the Judge.

[58]Mr Mellor submits that the passage just quoted from paragraph 50 displays an error in approach. One does not approach a prior art reference on the basis of “anticipation or nothing”. Nor is a modification obvious only if Bagautdinov points clearly to it. Rather, the correct test is whether Claim 4 would be obvious to the skilled person reading Bagautdinov with his common general knowledge in 1991. According to Mr Mellor, the judge misdirected himself. Indeed, he did not properly consider the common general knowledge in his assessment of Claim 4 nor did he expressly address the test set out in Pozzoli.

[59]Mr Alexander says that this criticism is misplaced and that what the Judge said must be read in the context of the judgment as a whole. He refers back to paragraph 27 of the judgment where the Judge identified the spat about whether the method described in Bagautdinov was, on the one hand, just the removal of pus from a purulent wound (ie whether Bagautdinov was just to do with drainage) with treatment being discontinued as soon as the proliferative stage was reached or whether the method was, on the other hand and as S&N argued, actually a healing method which was the same as the method in the Patent. The Judge, observed (correctly I would add) that this was to a large degree irrelevant since the claims related to an apparatus rather than a method of treatment. He noted that so far as anticipation was concerned, the method would be relevant only to the extent that it helped resolve an uncertainty about the construction of the apparatus. However, so far as obviousness is concerned, he noted, again perfectly correctly, that the details of the method “may affect the question of what modifications from the original apparatus it might be obvious to the skilled person to make”.

[60]Mr Alexander submits that the Judge was saying nothing different in the last sentence of paragraph 50; the Judge was right, he contends, to say that the teaching and purpose of Bagautdinov are not to be ignored when addressing the issue of obviousness; they are factors, among many factors, to be taken into account. The Judge, according to Mr Alexander, is saying no more than that, if the prior art does point clearly to possible modifications of the apparatus, then one can ignore the teaching and purpose of Bagautdinov. That is, he says, a perfectly correct approach unless one were to put the cart before the horse and hold that a modification is a workshop modification without actually considering whether it is a modification that would in fact have been made or whether there is motivation not to make it

[61]What the Judge appears to have done, at least on one reading, is to do more than take the teaching and purpose of Bagautdinov into account. His starting point seems to be that the case is indeed one of “anticipation or nothing”: at least, he expressly records his sympathy with that view, apparently based on the opening of paragraph 50. That would be the wrong starting place.

[62]The view that the Judge has adopted this approach is supported by paragraph 51 of his judgment. He recorded the attack on Claim 4 (obvious to use an adhesive coated polymer film) as a good illustration of the “anticipation or nothing” argument. He proceeded through that paragraph and paragraphs 52 and 53 as though the onus were on S&N to displace the view that it was a case of “anticipation or nothing”. That is not the correct test. Let me leave the point aside for a moment, without deciding whether the Judge applied the wrong test, to address Mr Mellor’s other criticisms of these paragraphs.

[63]In the context of those criticisms, I need to address the Judge’s reference to the evidence of Dr Gordon in paragraphs 51 and 52. The first reference is to his evidence about the availability of non-adhesive film. I have already concluded that the evidence overall clearly established that all the commonly and readily available films were, in 1991, adhesive films with the exception of the 10,000 drape; but even that was adhesive along one edge.

[64]The second reference was to his evidence that it was therefore obvious to use an adhesive film. I need to spend a little time on this aspect of his evidence because Mr Alexander says two things about it. First, he says that Dr Gordon’s evidence was only about what he would have done and not what other people would have done; secondly, he says that it is in any case evidence which is based on hindsight. For these two reasons, it provides, he says, no evidence at all about what the skilled addressee would have done with Bagautdinov. Accordingly, one is left with what Mr Alexander describes as Dr Orgill’s cogent evidence leaving this court with no possible ground for interfering with the Judge’s decision, in accordance with Dr Orgill’s opinion, that Claim 4 was not obvious.

[65]Let us see what Dr Gordon actually said in his report and in cross-examination. In paragraph 99 of his report, he did indeed deal with what he would be likely to have done. But that is not all he said. He also referred to other surgeons saying this:

“All of these devices [this clearly refers back to the equipment generally, including film – any one of the self-adhesive films widely available] were widely available in operating rooms in 1991 and other surgeons would have similar training and experience that would make translating the teachings of Bagautdinov into a working apparatus easily accomplished.”

[66]Likewise, in paragraph 100 of his report, Dr Gordon refers to self-adhesive films being more readily available in 1991 to physicians than films without adhesive.

[67]There is nothing in Dr Orgill’s evidence contrary to those elements of Dr Gordon’s evidence.

[68]Those paragraphs of Dr Gordon’s report should also be read in the context of paragraph 44 where he explained that covering the wound with a flexible film to seal-in fluid was common in 1991. Commonly used films in 1991 included Tegaderm and Opsite, both of which were adhesive-coated. Another commonly used film was Ioban – again adhesive-coated – the same film as is referred to in the Patent in the preferred embodiment mentioned in paragraph [0023]. Dr Orgill agreed that these were well-known to those working in wound management.

[69]It is not fair, therefore, to say that Dr Gordon gave evidence only of what he would have done. He also said that other surgeons would have been able easily to turn the teaching of Bagautdinov into a working apparatus and it is clear from the context of paragraphs 99 and 100 that he means an apparatus using adhesive film. He does not, it must be accepted, refer to the skilled person and in speaking of surgeons he is referring to real surgeons in the real world. But evidence of what “other surgeons” – that is to say a generality of surgeons in the field – would or perhaps could have done is of relevance and part of the education of the Judge.

[70]So far as hindsight is concerned, this exchange took place in Dr Gordon’s cross examination by Mr Alexander:

“Q: For the film you say you would have used any one of the many self-adhesive films widely available at the time. It is right to say that that would have departed from Bagautdinov’s teaching, which is to use a film that is not adhesive and Vaseline; that is correct is it not? A: I do not know. Again this is one of the areas where hindsight clearly colours what I would say. I know my personality. If I have like two possibilities I can get some Vaseline and find some film that does not have adhesive on it. The challenge would be to find the film which does not have adhesive. I appreciate Dr Orgill’s comment. He mentioned the thousand drape [a film with adhesive along one edge]. We have some films in the OR that have some adhesive along the edge to tack them down. Other than that, all the other film I see in my practice comes with adhesive already there. So I guess that in 1991 I would say “let me go find some film, I don’t know where it is, without an adhesive” or “let me get the Tegaderm or the Ioban that is on the shelf over there”

. To me that is a no-brainer. I will go get the one that already has adhesive.”

[71]What this exchange shows is that Dr Gordon was well aware of the dangers of hindsight. But he was doing his best to say what he would have done without the knowledge which he now has about the Patent. His evidence must be treated with caution; but the Judge appears to have rejected it on the basis that it “could not give any indication as to what the notional skilled addressee working from Bagautdinov and in ignorance of the Patent would do”. I consider that that is putting matters too high. Dr Gordon’s evidence that this was to him a no-brainer as such is not evidence of what the ordinary addressee would have done (as always the temptation to equate the expert witness with the notional addressee should be resisted). But his reason for that opinion is surely relevant to the question whether it would have been obvious to a skilled person.

[72]I return to Mr Mellor’s criticisms of paragraphs 50 to 53 of the judgment.

[73]The first point relates to the suggestion in paragraph 51 that using a film with no adhesive makes it easier and more comfortable to the patient when the dressing is to be replaced and to the suggestion in paragraph 53 that the use of an adhesive polymer film would actually be contrary to the teaching of Bagautdinov who uses an easily removable polymer film. Mr Mellor points out, correctly, that Bagautdinov says nothing about his treatment being easy to use and comfortable for the patient nor about using an “easily removable” polymer film.

[74]As to the “easy removal and more comfortable” aspect, this teaching is actually to be found in a more recent document (not referred to by the Judge) which was put to Dr Orgill in cross-examination in the context of the need for a seal. This document made a comparison with the (by then) existing treatment using an adhesive film. Easy removal and comfort was not an aspect of the case explored in any detail in the evidence although pain on removal of adhesive film was mentioned, an aspect I will come to later.

[75]In any case, although it is true that the first treatment uses a film sealed by Vaseline, the second does not: it is a polyethylene sleeve attached with plaster. There is nothing at all to suggest that an adhesive film would have any disadvantage in terms of ease of removal and comfort as compared with the alternative treatment of Bagautdinov.

[76]So far as concerns the proposition that Bagautdinov actually teaches against the use of adhesive, the Judge apparently reached this conclusion because according to him Bagautdinov uses an easily removable polymer film. However, Bagautdinov does not use an easily removable polymer film in the second treatment so that, in relation to that treatment at least, the reason given by the Judge for his conclusion does not apply. The proposition that Bagautdinov teaches against the use of adhesive film is in my view inconsistent with the second treatment of Bagautdinov.

[77]Quite apart from that, the fact that a film sealed by Vaseline might be easily removable does not make it part of the teaching of Bagautdinov that an easily removable film must be used. The paper does not say so expressly. Nor does the Judge explain why he thinks – as he must have done to make the point about ease of removal – that an adhesive film could not also be easily removed, or at least easily enough not to cause any problem sufficient to cause the skilled team to put Bagautdinov in the bin. These were aspects which were not addressed in the evidence at trial. I consider that Mr Mellor is right in what he says.

[78]It follows that the Judge did make an error of principle. Perhaps he would not have done so if he had followed the Pozzoli structure. In particular if he had concentrated on the third step he would have put himself in the right position to answer the fourth, ultimately crucial question.

[79]For completeness, I should deal with what Dr Orgill says in paragraph 8.35 of his report about this aspect. One of the reasons he gives for saying it would not be obvious to use a suitable adhesive film is that the film in Bagautdinov needs to be removed after a short period of time (30 minutes to 2 hours) every day; the skilled person would not want to create more damage to the skin surrounding the wound, nor more patient discomfort, than necessary by using a sealing adhesive. This ignores, however, the teaching of Bagautdinov that continuous aspiration treatment could be used for patients with extensive purulent foci with a large amount of purulent secretion. Dr Orgill does not address this class of patient. His conclusion that the skilled person would not want to create more skin damage or patient discomfort simply does not follow since his premise leading to that conclusion is inapplicable in the case of such patients. I agree with Mr Mellor when he says that the Judge too appears to have overlooked this when considering Claim 4. The Judge’s reasoning on Claim 4 simply does not apply to this teaching.

[80]As to paragraph 52, Mr Mellor submits that the Judge disregarded (as classic hindsight) the evidence of Dr Gordon that he would have used an adhesive coated sheet to practise Bagautdinov. He says that it is unclear why this was hindsight, particularly in light of the evidence of both experts that the most commonly available films of the time were indeed adhesive-coated: this is not hindsight, but fact.

[81]I think that there is some confusion here. In paragraph 52, the Judge was reciting Dr Gordon’s evidence about what he actually did. That is, of course, a matter of fact. But the Judge’s point – and perhaps his reason for using the word “hindsight” – is, I think, that the reason Dr Gordon did what he actually did was because he had the benefit of KCI’s apparatus which he was trying to replicate. Accordingly, what he actually did was in the Judge’s view of no help in indicating what the skilled addressee without the benefit of the Patent would have done. I do not think the Judge can be criticised for taking that view.

[82]However, what the Judge did not, at least expressly, address was the evidence which Mr Mellor refers to that Dr Gordon would have used an adhesive-coated sheet to practise Bagautdinov even if he had now known about the Patent. That evidence is found in the passage from the cross-examination which I have already set out. What the Judge would have made of that evidence had he addressed it, I do not know. But I cannot conclude other than that he overlooked it when considering the obviousness of Claim 4.

[83]Mr Mellor’s next criticism is the failure of the Judge to address the evidence about the concern of possible dislodgment of the Bagautdinov apparatus, a problem which would be easily addressed by the use of a commonly-available adhesive film. The teaching of neither Bagautdinov nor the Patent addresses this problem. Mr Mellor explains that Dr Orgill had a concern that, if a film was applied using Vaseline as taught by Bagautdinov, there was a potential problem with it being dislodged; I suppose that this is one of the factors which it is said by Dr Orgill would put the skilled person off Bagautdinov in the first place.

[84]Be that as it may, Dr Orgill himself explained that his concern about dislodgment is met by the use of a drape material such as Tegaderm to get a seal. He accepted at one stage of his cross-examination that the Bagautdinov apparatus could be prevented from dislodging by use of tape, albeit that he remained concerned about leakage caused by movement which might damage the film. Mr Mellor returned to the subject: he put to Dr Orgill that if a person had a concern about displacement of the film and wanted to create a seal (another concern which Dr Orgill had in relation to Bagautdinov’s method according to the first treatment), a perfectly natural alternative would be for him to use the adhesive drapes that the skilled person was familiar with. Once the question had become more focused so as to relate to a skilled person in the US (rather than Russia) and once it was accepted by him that Bagautdinov required a seal (as the Judge held) he accepted that the person would use whatever he could get hold of to seal, that is to say the adhesive drapes to which Mr Mellor was referring.

[85]Now, Mr Mellor goes so far as to say that these answers show that, once Claim 1 has been held to be anticipated, Claim 4 is obvious: a person implementing Bagautdinov with concerns about sealing and dislodgment would see adhesive film as an obvious solution. I consider that that is going too far since there may be other reasons why the skilled person would not have proceeded with Bagautdinov at all and those reasons may make any development non-obvious. Nonetheless, those answers are significant in the overall assessment of obviousness. The Judge appears to have taken no account of this evidence.

[86]A further criticism relates to the failure of the Judge to take account of his own finding in paragraph 18 of the judgment that skilled people were used to changing dressing 1 to 4 times per day (perhaps every 3 hours therefore) often causing some degree of pain. Adhesive films were in common use and so were already being placed on, and taken off, the skin several times throughout the day. The Judge does not appear to take account of this in his assessment of obviousness; and yet it is clearly significant because it is a counter-argument to the suggestion that the skilled person would not have used an adhesive film because of the pain it caused on being removed.

[87]In my judgment, the criticisms which Mr Mellor makes of the Judge’s reasoning in relation to the obviousness of Claim 4 are established.

[88]I should now return to the submission that the Judge in fact applied the wrong test in assessing obviousness. It is not possible, in the present case, entirely to de-couple this submission from the criticisms which I have already addressed and found to be valid. By making the errors which he did, the Judge has, it seems to me, effectively put himself in a position where the case really does become one of “anticipation or nothing”. Whether this is properly to be regarded as an application of the wrong test and thus as a free-standing reason for overturning the finding of obviousness becomes a matter of semantics. What it is right to conclude, in my judgment, is that the Judge did not properly carry out that overall evaluation of the evidence which is required in order to form a conclusion about obviousness.

[89]It is now open to this Court to consider the question of obviousness and to reach our own conclusion applying the test as set out in Pozzoli.

Step 1: Skilled addressee and common general knowledge

[90]The nature of the skilled addressee and the state of the common general knowledge have already been considered (see paragraph and paragraphs 7 and 21ff above).

Step 2: Inventive concept of Claim 4

[91]The inventive concept of Claim 4 is to use the apparatus of Claim 1 with a sealing means which is a polymer sheet where the sheet has adhesive on at least a surface facing the wound to attach and seal to the skin.

Step 3: Identify the differences from the prior art

[92]Bagautdinov clearly teaches the use of the apparatus of Claim 1 with a polymer sheet (it uses the words “covered with a polyethylene film”). Bagautdinov also teaches, in the second method of treatment, the use of plaster to secure the polyethylene film in place when in the form of a sleeve. So the only difference is to practise Bagautdinov using a film with adhesive on at least a surface facing the wound to attach and seal to the skin.

Step 4: do the differences require invention?

[93]Mr Mellor submits that it is extremely difficult to understand why it would require any invention whatsoever to use an adhesive sheet to implement Bagautdinov. In fact, to do so would, he says, be entirely obvious.

[94]First, Mr Mellor says that the purpose of the film in Bagautdinov is to create a seal for the application of negative pressure. The film needs to be sealed to the skin. Although there had been a debate about the meaning of seal, the Judge held that the sealing which one finds in Bagautdinov does satisfy the relevant integer of Claim 1 and thus of Claim 4 as well. At the priority date, the most commonly used films in surgery were coated with adhesive specifically for the purpose of attaching to skin. They create a seal.

[95]Secondly, Mr Mellor says that a skilled person would be aware of the very practical concern of the apparatus being dislodged. I think that he must be right in saying that; clearly Dr Orgill (albeit rather more expert than the skilled addressee) thought it self-evident and expressed concerns about it. Bagautdinov teaches one method where the apparatus can be used either for a relatively short period (30 minutes to 2 hours) or, for extensive purulent foci, another method where the apparatus is used continuously. Dislodgment would be a concern in these cases. Ensuring the apparatus is secure on the patient is clearly to be desired.

[96]I have already referred to the evidence (not addressed by the Judge) about dislodgment in addressing Mr Mellor’s criticisms of the judgment. Although Dr Orgill was talking about his experience after the priority date, there is no reason to think that the problems of dislodgment were any different in relation to the Bagautdinov apparatus before that date.

[97]Mr Mellor submits that it would have taken no invention for a skilled person in 1991 who wanted to secure the Bagautdinov apparatus on the patient, to use an example of one of the flexible adhesive films then in common use, just as Dr Orgill and his team do today. This, he submits, was the obvious choice then as now. Indeed, as I have already shown, the evidence is that it would have been difficult by 1991 to find a film which was not adhesive.

[98]Finally, Mr Mellor submits the method of sealing the film is not what is important in Bagautdinov. Bagautdinov itself teaches that the sealing of the film can be done by smearing with sterile Vaseline or salve (which have adhesive properties) or by the use of plaster. The use of specially adapted adhesive films is, according to him, just another such method. He submits that, faced with the overwhelming prevalence of adhesive coated films for surgical/wound management use in 1991, Bagautdinov would have to have had strong teaching to direct the skilled person away from such use. Such teaching is entirely absent. Not only were all the commercially available films pre-coated with adhesive specifically for use on skin but their use ensured both that the film was sealed and would not be dislodged. Absent clear direction to the contrary, their use was (in the words of Dr Gordon) a “no-brainer”, an aspect I have already dealt with.

[99]How do Wake Forest and KCI meet this case on obviousness? There is no argument which they can raise in relation to Steps (1) to (3) of Pozzoli. Instead, their case rests on two planks. The first is that there was no evidence of obviousness on which the Judge could have relied, let alone on which an appellate court could overturn his findings. The second is the proposition that the skilled person in 1991 would have seen no reason to embark upon any development of Bagautdinov. Mr Alexander accepts, as he must, that the skilled person will have read Bagautdinov and have done so carefully but with no imagination. His case is principally that the paper would simply have been put aside and would not have been seen as any more worthy of consideration than other material. The skilled person would have had no motivation to take Bagautdinov forward. In that context that he relies on the paper by Dr Orgill and Dr Hemling to show what areas of development were of interest to those active in the field, areas which did not include bio-mechanical means such as Bagautdinov’s apparatus. He does not, in any case, accept that the allegedly inventive step of Claim 4 would be obvious even if it is accepted that Bagautdinov was being implemented.

[100]In this context, Mr Alexander developed before this Court, as he did below, his arguments about the method and purpose of the Patent as compared with Bagautdinov. Interesting as they were, I do not propose to address those arguments because, in the context of the claims in dispute – which are apparatus claims – it is sufficient, in order to establish obviousness, that the use of an adhesive film is an obvious development of the apparatus for the methods and purposes envisaged by Bagautdinov. Mr Alexander accepted that that was correct in principle.

[101]I should, nonetheless, mention Mr Alexander’s argument that Bagautdinov was dealing with the application of suction over a short period to clean the wound – up to 2 hours. In contrast, the invention of the Patent is designed to apply negative pressure for lengthy periods of therapy. That may be so; but it has nothing to do with whether or not it would be obvious to use an adhesive film for precisely the same purpose and in the same conditions as the Bagautdinov apparatus. The question is not whether the methods of the Patent are novel – they may well be although not capable of being the subject matter of a valid patent – but whether the change to the apparatus is obvious.

No evidence of obviousness

[102]Returning to Mr Alexander’s main arguments, he submits that there was no evidence of obviousness. I have already dealt at some length, in considering Mr Mellor’s criticisms of the judgment, with the evidence concerning the obviousness of Claim 4 namely paragraphs 44, 99 and 100 of Dr Gordon’s report, paragraph 8.35 of Dr Orgill’s report and the cross-examination of each of them. I do not consider it is correct to say that there was no evidence from Dr Gordon about obviousness; nor can Dr Orgill’s evidence be seen as uncontroverted or incontrovertible evidence to establish the Claim 4 was not obvious. I take account of all of the evidence in reaching my own assessment of obviousness.

[103]However, in further support of his case, Mr Alexander submits that there is no evidence that anyone ever tried to adapt Bagautdinov to treat the sort of wounds with which the Patent is concerned; nor that anyone contemplated making the changes which S&N submit were obvious; and that this is so even though the contemporary records surrounding Bagautdinov show that there was an urgent hunt on in Russia for improved methods of wound healing; and it is common ground that all of the means for doing so were readily available.

[104]I must treat all of that with some care. There is actually no evidence that anyone ever used Bagautdinov at all other than in relation to the 170 cases mentioned in Bagautdinov itself. There is no evidence that Bagautdinov needed any adaptation to treat (in terms of Bagautdinov itself) the sort of wounds with which the Patent is concerned (in the sense of the focus of the description, large wounds: the actual claims are not restricted to large wounds). Nor is there any evidence that anyone (even in Russia) actually knew of Bagautdinov; I think it may safely be assumed that no-one involved in this litigation had ever heard of it until a diligent search was carried out to find some prior art of relevance. I do not consider that these considerations assist in resolution of the issues.

[105]There is, in this context, one important additional point to make (or repeat) which is that neither Dr Gordon nor Dr Orgill identified a film in common use in 1991 which was not adhesive; yet an adhesive film is all that Claim 4 adds to Claim 1. So, once the skilled person has decided to consider Bagautdinov in the first place, the argument that the use of an adhesive film as an obvious way of implementing it appears to me to be irresistible.

Bagautdinov as the starting point and motivation

[106]Mr Alexander asks why should the skilled reader of Bagautdinov single it out, even from all of the other pus drainage papers, let alone all of the others on treatment of wounds generally? To answer his rhetorical question on the facts, one very good reason might be because the notional fictional skilled addressee who is deemed by law to have read the prior art items individually will have noted the 100% success in 170 cases.

[107]So let me look at the more specific reasons given why Bagautdinov might not be a good starting point and why the skilled person might have no motivation to do anything with it at all.

[108]Two reasons relied on are to be found in paragraphs 8.16 and 8.17 of Dr Orgill’s report. Clearly Dr Orgill did not think that Bagautdinov would be a starting point for a skilled person. The skilled person would, according to him, have been put off by two things in particular. First, the recommendation that one should leave a pus-filled foam sponge in the wound for a lengthy period which was contrary to good medical practice. It would lead to infection. Second, the questionable quality of the paper.

[109]As to the first of those, Mr Alexander refers to it as “plainly inappropriate teaching”. This takes us back again precisely to the issue addressed by the Judge in paragraph 32 of the judgment. It was rejected by the Judge. I consider that he was right to do so for the reasons which he gave.

[110]As to the second, Mr Alexander says that another important aspect is that the paper states expressly that it had no proper statistical support. He says that, generally, the paper is unpersuasive and unattractive and certainly gives the skilled reader no reason to attempt to experiment with or modify the materials of methods described. This again was an aspect addressed by the Judge. He was right, I consider, to regard this feature as inadequate to deter the skilled reader.

[111]There are other reasons put forward by Mr Alexander why the skilled person would be put off considering Bagautdinov or would have no motive to implement or develop it or that he would not be interested in it:a. The skilled person would not be trying to create a seal as this is not necessary for aspiration and adds unnecessary complications. This was the first reason given for non-obviousness in paragraph 8.35 of Dr Orgill’s report. I reject it because, as found by the Judge, Bagautdinov does teach the need for a seal and an adhesive film would be an obvious way of providing a seal. There is no evidence of “unnecessary complications” other than ones which I expressly address in this judgment (ease of use, comfort, pain).

b. The skilled person would not want to create more damage nor patient discomfort than necessary. I have already dealt with this aspect; they would not, in my judgment, deter the skilled person from implementing Bagautdinov with adhesive film, particularly bearing in mind the second treatment of Bagautdinov which probably uses sticky tape if not adhesive film.

c. The pain caused to patients by the placing and removal of the adhesive film up to 4 times a day. The evidence shows that skilled people were used to changing dressings up to 4 times a day as I have explained already, causing some pain and discomfort to the patient. This is a pretty poor starting point for an argument that the skilled person would be put off implementing Bagautdinov by using film which would cause the same pain. I agree with Mr Mellor when he says that this suggestion that the skilled person would be put off is unreal. As he puts it, the concern which a skilled addressee might have about the pain caused by used of an adhesive film in 1991 is at best, from Wake Forest’s point of view, a “lion in the path”. But there is no lion: adhesive films were

(i) the most commonly available films for the skilled person to use

(ii) perfectly and obviously suited for the purpose and method of Bagautdinov and

(iii) had the added advantage of ensuring that the apparatus was firmly secured.

d. The difficulty that the foam dressing would stick to the adhesive film, thus creating problems when the film came to be removed at the end of a period of the treatment – the foam is intended following Bagautdinov to remain in the wound. This was a matter which was not gone into at trial. The point is not found in the evidence and was not made at trial. It is a new point raised by Mr Alexander on this appeal. It is not open. Even if it were, there must be great force in Mr Mellor’s suggestion that the skilled person would readily cope with the problem.

[112]Accordingly, I do not consider that any of the reasons put forward by Mr Alexander to show that the skilled person would be deterred from implementing Bagautdinov with adhesive film stand up to examination. If a skilled person in 1991 were to have implemented Bagautdinov at all, it would have been obvious to him that one method of doing so would be to use adhesive film. Similarly, a skilled person considering in 1991 whether to implement Bagautdinov would see the use of adhesive film as an obvious way of doing so if he were to proceed. Having read Bagautdinov, the skilled person would have seen the 100% success in relation to the 170 patients referred to in the paper. The skilled person would have a sound reason for thinking that the method worked. I might add, in this context, that even Dr Orgill did not give evidence to the effect that the skilled person would not be interested in Bagautdinov in the first place and would not even consider it worth implementing at all.

[113]In these circumstances, I consider that Claim 4 is obvious.

Claims 16 and 19

[114]The Judge deals with anticipation very briefly. Relevantly, he says this in paragraph 48 of his judgment:

“Claim 16…..requires the vacuum means to operate cyclically and claim 19 is dependent on claim 16 but stipulates a ratio of application to no-application periods between about 1:10 and 10:1. Bagautdinov applies pressure for a period of time and then removes the plastic film. The treatment is repeated the following day. That is not what the Patent refers to as “cyclically”

. Neither of these claims is anticipated by Bagautdinov.”

[115]Mr Mellor submits that Claim 16 is in fact anticipated. His written argument contained no hint of that and his oral submission was brief. After referring to paragraph 48 of the judgment, he said that “….if you take Bagautdinov two hours a day, so you have two hours on 22 hours off, you are not very far. You are actually 11 to 1 but the judge says this is not what the patent refers to as cyclically”

[116]Mr Mellor said nothing else about anticipation. The argument does not begin to explain why Claim 16 is anticipated. I reject the suggestion that Claim 16 is anticipated. Claim 19 cannot therefore be anticipated either.

[117]In relation to the obviousness attack,

the Judge says this in paragraph 56 of his judgment:

“Claims 16 and 19 related to the cyclic application of vacuum. Bagautdinov teaches the application of a vacuum for relatively short period followed by the removal of the sealing means. This does not involve use of a vacuum means which can cycle on and off. To use such vacuum means would involve a treatment quite different from what Bagautdinov teaches and there is no reason to make the variation in the absence of hindsight. The claims are obvious.”

[118]The Judge does not in these paragraphs refer to the continuous use which Bagautdinov teaches. However, that is not a material distinction for present purposes.

[119]Mr Alexander refers to the advantages which cyclical application provides and remarks on the fact that Dr Gordon himself regarded the lack of a cyclical function as a limitation on his own home-made equipment. No-one had thought, by the priority date, of using cyclical pressure in the treatment of wounds even for removing pus. After all, he asks, what would be the advantage of pulsing a vacuum cleaner? Accordingly, the Judge’s decision was inevitable; it is, he says, difficult to think of any reason why a person implementing Bagautdinov would want to have the cyclical function for any purpose.

[120]But all this, it seems to me, is to confuse the method of treatment with the apparatus. The teaching of Bagautdinov is to apply negative pressure whether for a relatively short period or continuously. It is true that Bagautdinov does not teach using negative pressure cyclically, but it says nothing which would prevent the use of an apparatus which, as well as a perfectly conventional “on/off” switch had a cyclical function even if that function were not used in implementing Bagautdinov.

[121]The fact is that, by the priority date, there was a well-known vacuum pump called a Gomco pump. This was a portable vacuum pump which travelled on wheels and could provide a continuous or intermittent vacuum. Although the most common use of the Gomco pump was for nasal gastric tube drainage, Dr Gordon’s evidence was that these pumps were also sometimes used for drainage (in the context of the questioning, this must be wound drainage). He said that they were in common use in the 1970s and 1980s but were still in use today; clearly he considered that they were common general knowledge in 1991. It was suggested to him that the Gomco pump was old technology – although what is said to follow from that I am not sure. He agreed that they were old technology but were still used in hospitals “like many others we still use, like electric lights”.

[122]Dr Orgill accepted that the Gomco pump was available in 1991 and that he himself used them frequently (although the questioning did not go to the purpose for which they were used).

[123]The Judge does not refer to any of the evidence. However, I see no reason to conclude other than that the Gomco pump was in 1991 common general knowledge. The Gomco pump was clearly suitable for implementing Bagautdinov. In my judgment, it would take no invention in 1991 to implement Bagautdinov using a Gomco pump. It makes no difference to that conclusion that the skilled person might not have used, or even thought of using, the intermittent setting. In my judgment, Claim 16 is obvious.

[124]I would add two observations. First, Bagautdinov expressly teaches that the treatment can be used under outpatient clinical conditions; there is nothing to suggest that all outpatient facilities would have wall vacuum sockets, especially in Russia. Reference to the Gomco pump (or indeed any other mobile vacuum source) cannot be avoided by a suggestion that the skilled person would consider only a wall vacuum (which is continuous) for the implementation of Bagautdinov. Secondly, if Claim 16 were valid, it would follow that it would be infringed by a person implementing Bagautdinov with a Gomco pump; he would be using an apparatus suitable for cyclical application. The fact that he might use it only on the continuous setting would not prevent infringement. This would be an odd result (although I should say that this does not form part of my reasoning).

[125]Claim 19 falls, in my judgment, with Claim 16. If it is obvious to use a pump which is capable of operating cyclically, then that pump must necessarily be suitable to operate within the ratios specified in Claim 19. It is irrelevant whether, as a method of treatment, operation within those ratios would be novel. The Claim adds nothing over Claim 1.

Further cross-appeals

[126]Wake Forest and KCI had further cross-appeals in relation to Claims 2, 8 & 9, 13 and 15. These were not pursued.

Conclusion

[127]The appeal on the obviousness of Claims 4, 16 and 19 is allowed. The appeal and cross-appeal in relation to Claim 1 are dismissed. The other cross-appeals are dismissed. APPENDIX “Variant of External Vacuum Aspiration in the Treatment of Purulent Diseases of Soft Tissues” by N.A. Bagautdinov Active drainage of purulent wounds with lengthy vacuum aspiration promotes outflow of tissue fluid from the walls of the wound and its cavity, a reduction in perifocal edema, intratissue pressure, an improvement in blood and lymph circulation, a collapse of the cavity and limitation of the infectious focus. In essence it is a method of physical treatment of antisepsis of the purulent focus and a means to accelerate healing of the wound process (N.N. Kanshin, 1990; E. Ya. Ersh, 1984; S.V. Lokhvitskii, 1984 and others). For vacuum treatment of purulent-inflammatory diseases in soft tissues and unclosed sutures of purulent wounds, an apparatus of the “blood suction cup” type is now used (A.Bir, 1906), which is placed on the skin n the area of the inflammation focus. Vacuum treatment is accomplished in the range 10-500 mmHg below atmospheric pressure for 3 to 5 seconds to a few hours, which is often determined not by scientific-clinical argumentation but also the subjective viewpoint of the physician. Recognizing all the positive aspects of active external vacuum aspiration (AEVA) we believe that it has significant shortcomings which can come down to the following main views. 1. The periphery of the working part of the vacuum devices should correspond to the shape and dimensions of the skin defect of the wound. Otherwise vacuum treatment occurs in the surrounding tissues beyond the pathological focus, where ischemic disorders develop, bleeding and the most important thing, the conditions are created for spreading of the purulent infection especially at high vacuum. 2. When wounds are localized in the area of bone protrusions and physiological bends in the surface of the body hermetic installation of the vacuum device is either impossible or associated with overcoming major technical difficulties. 3. Use of gauze, rubber strips and tubes as drains does not ensure uniform vacuum treatment of the entire cavity (surface) of the wound, which leads to adhesion of the walls, difficulties in outflow of the wound secretion and products of necrolysis. We propose and introduced in clinical practice a method for vacuum treatment of primary and secondary purulent wounds which is devoid of the aforementioned shortcomings……. The treatment consists of the following. After surgical treatment of the purulent wound and hemostasis, a drain of polyurethane foam adapted in shape and size is placed on the surface (or in the cavity). The surrounding skin is smeared with sterile vaseline, antiseptic or inert salve on an oil base and covered with a polyethylene film. During localization of the purulent abcess on the forearm, shoulder, shin and thigh, isolation from the atmosphere is accomplished with a polyethylene sleeve which is attached to the skin on the periphery of the segment of the extremity distal and proximal to the wound with plaster. For isolation of the hand, its fingers and the feet, polyethylene sacks of the corresponding size are used by attaching them to the skin by a similar method proximal to the wound. Regardless of the method of sealing, a tube is hermetically installed through a hole in the polyethylene made beforehand. The latter is connected to the vacuum pump through a collection vessel. At a vacuum of 10 to 60 mmHg the film encloses the wound strictly along its skin boundaries with uniform vacuum treatment of the walls only on the side of the cavity and elimination of exudate because of the porous structure of the drain. The duration of the treatment session depends on the degree of vacuum and ranges from 30 minutes to 2 hours, whereupon the polyethylene is removed and a gauze bandage emplaced. The sessions are conducted daily until the wound is clean. On average this procedure takes 3 to 4 days. In patients with extensive purulent foci with a large amount of purulent secretion continuous aspiration treatment was conducted using a tube above the polyurethane with a U shape. A mini-irrigator was passed through one branch through an elastic plug and then to the wound and the second branch was connected to suction. The polyurethane foam has a good suction effect. After 24 hours the polyurethane foam drain was impregnated with wound secretion in an amount 10 times exceeding the weight of the drain. Cleaning the wound occurred on average in four to five days after surgical treatment, which was checked by the pH, total protein content in the exudates, the dynamics of the change in the area and volume of the wound [it is common ground that this is granulation] and the results of cytological studies by surface biopsy according to M.F. Kamaev. In 50% of patients with extensive wound defects primary emergency or early secondary sutures were then emplaced. In all cases the wounds healed without complication. During comparative evaluation with the traditional methods of treatment (170 observations) we inevitably obtained acceleration of the healing periods and rehabilitation of the patients. Statistical data confirming the effectiveness of the recommended method is not given here because of the inadequate number of patients in the representative groups. Conclusions. The proposed variant of treatment of purulent diseases of soft tissue is technically simply and clinically effective. Vacuum aspiration in our modification accelerates cleaning and sealing of purulent wounds and cavities. It could be performed both under hospital conditions and under outpatient polyclinical conditions.

[128]I agree.

[129]I also agree.