Kimberly-Clark Australia Pty Limited v Multigate Medical Products Pty Limited

Kimberly-Clark Australia Pty Limited v Multigate Medical Products Pty Limited - [2011] FCAFC 86 - FCAFC 2011 case summary — Zoe

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THE PATENTS 4 The claimed invention of the Patents is directed to sterilisation wrap materials. More particularly, the invention is directed to multi-plied materials made from individual sheets, which are fused together so as to be suitable for use as a wrap for surgical instruments and supplies for the purpose of sterilisation. Certain surgical instruments and supplies used in operating rooms of hospitals are reusable. Such instruments and supplies must be collected after each procedure and sterilised before they can be reused in another procedure. After sterilisation, the instruments and supplies are generally wrapped with two sheets of material, commonly referred to as sterilisation wrap. The sterilisation wrap is usually a woven or non-woven material that, when wrapped around the instruments and supplies in a particular manner, will permit the entry of vapour, gas or another medium to sterilise the instruments or supplies, while denying the ingress of contaminants, such as bacteria and other infectious materials, after the sterilisation has been effected. The two primary means for sterilising are autoclaving with steam and ethylene oxide sterilisation. 5 Once the wrapped instruments and supplies have been sterilised, the package is stored until it is needed, or it is transported to a point of proposed use, such as an operating room. During storage and transfer to the operating room, the wrapped package may be handled several different times. Each time the package is handled, there is the potential for the sterile nature of the contents of a package to be compromised, for example by a tear or other breach of the wrapping material. To prevent the consequences of a breach or tear of the material, it has become common practice in many hospitals to double wrap packages. 6 A primary method of double wrapping is sequential, in that the instruments or supplies are first wrapped in one sheet of sterilisation wrap and then wrapped again in a second sheet of sterilisation wrap. A second method of double wrapping is simultaneous, in that the instruments or supplies are wrapped in two sheets of sterilisation wrap at the same time. That is to say, two sheets of sterilisation wrap are aligned, one on top of the other, the instruments or supplies are placed on top of the two sheets and the instruments or supplies are then wrapped in both sheets of material at the same time. If the outer and inner sheets of the double wrap have different properties, it is important that the sheets be visually identifiable so that the user can determine which wrapper is the outer sheet and which wrapper is the inner sheet. 7 The time that it takes to set up the outer and inner sheets and the awkwardness of manipulating loose sheets during simultaneous wrapping can make inroads into time savings that might otherwise be achieved when adopting simultaneous wrapping rather than sequential wrapping. Accordingly, a product that provides the appropriate inner and outer sheet combinations, and eliminates the awkwardness of keeping the two sheets together during the wrapping and opening processes, would provide benefits such as time savings and targeted engineered inner and outer sheet performance. Thus, the Patents identified a need for a sterilisation wrap system that would reduce the time for packaging and opening and would deliver inner and outer sheet engineered performance in a simply identifiable and easy to use fashion. The complete specifications for the Patents assert that the claimed invention of the Patents provides those attributes. 8 Kimberly-Clark contends that Multigate's product would infringe claim 1 of the grandparent patent, claims 19 and 25 of the parent patent and claims 47 and 236 of the child patent. The precise terms of those claims are set out in the Appendix to these reasons. The substance of the claims may be summarised as follows: Claim 1 of the grandparent patent is for a method of sterilising an article in which an article is wrapped with a sterilisation wrap consisting of an inner wrap sheet and an outer wrap sheet. The wrapped article is then exposed to sterilising conditions for a sufficient time so that the article is sterilised. Each sterilisation wrap sheet consists of a laminate. The sheets are joined together at a plurality of bond sites that occupy no more than 50 percent of the surface area of either of the sheets. To separate the joined sheets, at least one pound tensile force must be required. The sheets must be visually distinguishable as separate sheets. Claim 19 of the parent patent is for a product, being a sterilisation wrap system consisting of a sterilisation wrap that has a substantially flat inner wrap sheet joined to a substantially flat outer wrap sheet. The inner wrap sheet and the outer wrap sheet are to be visually distinguishable. Each sheet is formed from a laminate comprising a spunbonded layer and a meltblown layer, and the sheets are joined together by a plurality of bond sites arranged to provide visual distinction between the inner wrap sheet and the outer wrap sheet. Claim 25 of the parent patent is for the sterilisation wrap system of claim 19, where each sheet of the sterilisation system comprises a second spunbonded layer next to the meltblown layer. Claim 47 of the child patent is also for a product, being a sterilisation wrap system consisting of an inner wrap sheet having a peripheral edge and an outer wrap sheet having a second peripheral edge. At least a portion of the first peripheral edge is aligned with, but not joined to, a portion of the second peripheral edge. The inner wrap sheet and outer wrap sheet are joined to one another at one or more points within the area surrounded by the peripheral edges. Claim 236 of the child patent is also for a product, being a sterilisation wrap system consisting of an inner wrap sheet and an outer wrap sheet that is joined to the inner wrap sheet, such that the inner wrap sheet and the outer wrap sheet are visually distinguishable as separate sheets. 9 Kimberly-Clark contends that the Multigate product would infringe one or more of those five claims. Multigate denies that its product would infringe any of the claims because of the absence of several integers of the various claims. However, the principal basis upon which Multigate says that its product does not infringe is that Multigate's product achieves double wrapping by folding one piece so as to form two layers and not by joining two separate pieces. It says that each of the five claims in question requires both an inner wrap and an outer wrap that are separate from each other. 10 It might be thought that the solution of joining the sheets together, in response to the problem of awkwardness in dealing with two separate sheets, was obvious. However, lack of an inventive step has not been raised by Multigate. 11 The primary judge concluded that each of the five claims, on its proper construction, is limited by a requirement that the inner wrap sheet and the outer wrap sheet consist of two previously unconnected pieces of wrapping material that have been joined together. Accordingly, her Honour concluded that Multigate's product does not infringe any of the claims, because it consists of a single sheet that is folded over to create two layers.

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RELEVANT LEGAL PRINCIPLES 12 It is for the Court to construe the language of the claims. The principles guiding construction are not significantly different from those applicable to the construction of any other written instrument. Ordinary words should be given their ordinary meaning unless a person skilled in the relevant art would, in the context of the claims, give a special meaning or unless the complete specification ascribes a special meaning to the words of the claim. Expert evidence may be given in support of a claim that a word has a technical meaning. However, in the absence of a special technical meaning, expert evidence is not determinative of the construction of the claims. As meaning may vary with context, it is necessary, with any question of construction, to read the whole of the relevant instrument, whether or not there is any apparent ambiguity in the language to be construed. Ultimately, however, it is the claims that are to be construed, and the context provided by the complete specification cannot limit, vary or qualify the clear meaning of the claims. 13 The author of a document such as a patent specification uses language to make a communication for a practical purpose. A rule of construction that gives that language a meaning differing from how that language would have been understood by the persons to whom it is addressed is liable to defeat the author's intentions. Thus, a patent specification should be given a purposive construction rather than a purely literal one derived from applying to it a meticulous verbal analysis. Construction of a patent is not subjectively concerned with what the author meant to say. Rather, it is objective, in the sense that it is concerned with what a reasonable person to whom the patent is addressed would have understood the author to be using the words to mean (see Kirin-Amgen Inc v Hoechst Marion Roussel Limited (2004) 64 IPR 444 at [30]-[32]). 14 The notional addressee of a patent is a person skilled in the art to which the patent relates. That person comes to a reading of the specification with common general knowledge of the art, and reads the specification on the assumption that its purpose is both to describe and to demarcate an invention. The purpose of a patent specification is simply to communicate the idea of an invention. An appreciation of that purpose is part of the material that is used to ascertain the meaning. However, purpose and meaning are different. Purposive construction does not mean that one is extending or going beyond the definition of the technical matter for which the patentee seeks protection in the claims. The question is what a person skilled in the art would have understood the patentee to be using the language of the claim to mean. Accordingly, for that purpose, the language chosen is of critical importance. The specification is a document in words of the patentee's own choosing, which will usually have been chosen upon skilled advice (see Kirin-Amgen v Hoechst Marion Roussel at [33]).

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The Complete Specifications 23 Examination of the body of the complete specification provides the context within which the relevant claims are to be construed. Significantly, each of the complete specifications begins by saying that the claimed invention is directed to multi-plied materials made from individual sheets. That phrase indicates separate sheets, as distinct from a single sheet folded over. 24 The problem to which the claimed invention is directed is the inconvenience of manipulating two sheets of sterilisation wrap, aligned one on top of the other, such that a package can be wrapped by both sheets of material at the same time. The complete specifications also speak of the time that it takes to set up the outer and inner sheet wrappers and the awkwardness of manipulating loose wrappers during the simultaneous wrapping. The specifications also refer to the awkwardness of keeping the two sheets together during the process of wrapping and opening. 25 Kimberly-Clark accepts that the solution of the claimed invention of the Patents is directed to solving the problem of the awkwardness of keeping two separate sheets together and the delay involved in doing so. It says that there is nothing to be found in the solution provided that would preclude a single sheet being folded over in order to create two sheets for the purposes of double wrapping. The fact that the body of each complete specification describes advantages, without requiring that there be two separate sheets, indicates an acceptance, so Kimberly-Clark says, that a single sheet folded over would perform precisely the same function as two separate sheets joined together. That may be so. However, there is certainly nothing contained in any part of the complete specification that suggests that the solution propounded was to fold over a single sheet. 26 Significantly, the body of each specification also refers to a benefit, said to be achieved, of enabling targeted engineered inner and outer sheet performance. That is to say, the specifications clearly contemplate that the qualities of the inner sheet and outer sheet may be different from each other. The specifications refer specifically to the possibility that the outer and inner sheets have different properties, such that it is important that the user can determine which wrapper is the outer sheet and which wrapper is the inner sheet. That could not possibly be of any concern if the inner sheet and the outer sheet were simply a single sheet folded over. The fact that the two sheets have different properties is clearly inconsistent with use of a single sheet. 27 Later in their course, each complete specification refers to a particular feature of the claimed invention as being the specific tailoring available for each of the layers in the respective outer wrap and inner wrap. The specifications say that, while the two wraps can be identical to one another, in more refined embodiments the outer wrap is designed to have different strength properties from the inner wrap. Such a feature would be nonsensical in relation to an inner wrap and an outer wrap created by merely folding over a single sheet. 28 The body of each complete specification also refers to the importance of the end user's being able to determine which of the two wraps, inner or outer, should be placed adjacent to the package being wrapped and subsequently sterilised. To that end, the specifications suggest that the inner and outer wraps can and should be designed so as to be visually distinct from each other, such that a majority of people who routinely use these materials would be able to tell the difference between the first exterior surface and the second exterior surface based upon a visual observation of the two surfaces. One means of achieving that is said to be the shading or colouring of the inner wrap differently from the outer wrap. That is not the language of a single wrap folded in half. Rather, that language clearly indicates physically separate sheets rather than a single sheet folded in two. 29 Kimberly-Clark contends that the reference to the possibility of the inner sheet and the outer sheet having different properties or being visually distinct is no more than a possibility. That is to say, it asserts that it is no part of the claimed invention that it must be possible for the sheets to have different properties or be visually distinct. References to those possibilities are asserted simply to refer to a feature of the claimed invention and not to indicate a requirement of it. Nevertheless, the possibilities tend to support a construction of the claims that is consistent only with there being two separate sheets that have been joined together. 30 In describing the preferred embodiments by reference to the drawings attached to the complete specifications, each specification states that the outer wrap and the inner wrap are attached to one another in a manner whereby the two wraps are held together while still maintaining their visual distinctiveness, so that the end user can see that the item is being wrapped by two separate sheets of sterile wrap, which is said to be an important feature of the claimed invention. Being able to see the two separate sheets of sterilisation wrap is said to reinforce the comfort level of the user that the wrapped item is protected by not one but two sheets of sterilisation wrap. Thus, the specification says, the two sheets should be joined to one another with a sufficient amount of bonding that they do not separate, but not with so much bonding that the two sheets appear to be one. Those references are indicative of separate and discrete sheets. 31 The specifications also state that the two sheets of wrap should be sufficiently joined to one another that they do not readily separate from one another throughout the process of removing the sterilisation wrap from its packaging, wrapping the items to be sterilised and unwrapping the sterilised items for use. Thus, it is said, it is desirable that there be at least a one pound tensile force needed to separate the joined sheets from one another. That language is inconsistent with the notion that the two sheets are but a single sheet folded over.

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CONCLUSION 32 Examination of the language of the claims in question, in the context of all of the complete specification, indicates that the primary judge made no error in reaching her conclusion concerning the construction of the claims. There would be no infringement by Multigate's products. It follows that the appeal must be dismissed. Kimberly-Clark must pay Multigate's costs of the appeal. 33 The cross-appeal is based on the premise, which Multigate contends to be false, that the claimed invention of the Patents extends to a sterilisation wrap consisting of a single sheet folded over. Multigate accepts that, if the construction for which it contends, and which the primary judge accepted, is accepted by the Full Court, the cross-appeal cannot succeed. That is to say, if the construction contended for by it is accepted by the Full Court, such that the appeal is dismissed, the cross-appeal should also be dismissed. Accordingly, in the light of the conclusion reached above, the cross-appeal should also be dismissed 34 It is clear that Multigate impugned the validity of claims of the Patents only on the assumption that the construction of the claims contended for by Kimberly-Clark was the correct construction. Multigate has prevailed on that question. Nevertheless, it made the tactical decision to file a cross-appeal. The primary judge dealt with the substance of the cross-claim on the assumption that her Honour's conclusion as to construction was incorrect. Multigate could have accepted that the only question in the appeal was construction. Of course, in that event, if it had been unsuccessful, it would not have had the fallback of possible invalidity. 35 In the cross-appeal, Multigate was in effect advancing Kimberly-Clark's contentions on construction. Kimberly-Clark failed on those contentions. In all of the circumstances, the appropriate course is to make no order as to the costs of the cross-appeal. I certify that the preceding thirty-five (35) numbered paragraphs are a true copy of the Reasons for Judgment herein of the Honourable Justice Emmett.

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APPENDIX The Relevant Claims Claim 1 of the grandparent patent A method of sterilizing an article comprising: providing an article; wrapping the article with a sterilization wrap which comprises an inner wrap sheet and an outer wrap sheet; and exposing the wrapped article to sterilizing conditions for a sufficient time such that the article is sterilized; wherein each sheet comprises a laminate which comprises a first spunbond layer, a meltblown layer and a second spunbond layer and the sheets are joined together at a plurality of bond sites which occupy no more than 50% of the surface area of either of the sheets such that said sheets are visually distinguishable as separate sheets; and wherein at least one pound tensile force is required to separate said joined sheets. Claim 19 of the parent patent A sterilization wrap system comprising: a sterilization wrap having a substantially flat inner wrap sheet joined to a substantially flat outer wrap sheet such that said inner wrap sheet and said outer wrap sheet are visually distinguishable; wherein each said sheet is formed from a laminate comprising a spunbonded layer and a meltblown layer; and wherein said sheets are joined together by a plurality of bond sites, said bond sites arranged to provide the visual distinction between said inner wrap sheet and said outer wrap sheet. Claim 25 of the parent patent The sterilization wrap system of claim 19 wherein each sheet of the sterilization wrap system comprises a second spunbonded layer next to the meltblown layer. Claim 47 of the child patent A sterilization wrap system comprising: an inner wrap sheet having a first peripheral edge, and an outer wrap sheet having a second peripheral edge; wherein at least a portion of the first peripheral edge is aligned with and not joined to a portion of the second peripheral edge; and wherein the inner wrap sheet and outer wrap sheet are joined to one another at one or more points within an area surrounded by the peripheral edges. Claim 236 of the child patent A sterilization wrap system comprising: an inner wrap sheet and an outer wrap sheet joined to the inner wrap sheet such that the inner wrap sheet and the outer wrap sheet are visually distinguishable as separate sheets. IN THE FEDERAL COURT OF AUSTRALIA NEW SOUTH WALES DISTRICT REGISTRY GENERAL DIVISION NSD 1789 of 2010

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Relevant Legal Principles 38 The principles relevant to the construction of the patent specification are well established and there was no dispute between the parties as to what they are. A helpful summary is found in the joint judgment in Jupiters Ltd v Neurizon Pty Ltd (2005) 222 ALR 155 where the Full Court (Hill, Finn and Gyles JJ) said at para [67]: (i) the proper construction of a specification is a matter of law: Décor Corporation Pty Ltd v Dart Industries Inc (1988) 13 IPR 385 at 400; (ii) a patent specification should be given a purposive, not a purely literal, construction: Flexible Steel Lacing Co v Beltreco Ltd (2000) 49 IPR 331 at [81]; and it is not to be read in the abstract but is to be construed in the light of the common general knowledge and the art before the priority date: Kimberley-Clark Australia Pty Ltd v Arico Trading International Pty Ltd (2001) 207 CLR 1 at [24]; (iii) the words used in a specification are to be given the meaning which the normal person skilled in the art would attach to them, having regard to his or her own general knowledge and to what is disclosed in the body of the specification: Décor Corporation Pty Ltd at 391; (iv) while the claims are to be construed in the context of the specification as a whole, it is not legitimate to narrow or expand the boundaries of monopoly as fixed by the words of a claim by adding to those words glosses drawn from other parts of the specification, although terms in the claim which are unclear may be defined by reference to the body of the specification: Kimberley-Clark v Arico at [15]; Welch Perrin & Co Pty Ltd v Worrel (1961) 106 CLR 588 at 610; Interlego AG v Toltoys Pty Ltd (1973) 130 CLR 461 at 478; the body of a specification cannot be used to change a clear claim for one subject matter into a claim for another and different subject matter: Electric & Musical Industries Ltd v Lissen Ltd (1938) 56 RPC 23 at 39; (v) experts can give evidence on the meaning which those skilled in the art would give to technical or scientific terms and phrases and on unusual or special meanings to be given by skilled addressees to words which might otherwise bear their ordinary meaning: Sartas No 1 Pty Ltd v Koukourou & Partners Pty Ltd (1994) 30 IPR 479 at 485-486; the Court is to place itself in the position of some person acquainted with the surrounding circumstances as to the state of the art and manufacture at the time (Kimberley-Clark v Arico at [24]); and (vi) it is for the Court, not for any witness however expert, to construe the specification; Sartas No 1 Pty Ltd, at 485-486. 39 A patent specification may incorporate a definition of a word or expression which subsequently appears in the claims. Leaving that possibility aside, ordinary words which are used in a patent claim should be given their ordinary meaning unless the skilled addressee would give them a different meaning. There are words used in patent claims that have no ordinary meaning apart from their technical or scientific meaning. There are also words used in patent claims that have a technical or scientific meaning as well as an ordinary meaning. In the latter situation the words may have been intended to be used in accordance with their technical or scientific meaning or in accordance with their ordinary meaning. Expert evidence may be received to assist in determining which of these meanings was intended. 40 Difficulties of construction may still arise even if it is apparent that the words of a claim were intended to be given their ordinary meaning. This is because the ordinary meaning of words may vary depending on the context in which they are used. Thus, it is necessary to read a patent specification as a whole even if there is no apparent ambiguity in the language of the claims. 41 There are two aspects to the principle which requires that a patent specification be given a purposive rather than a purely literal construction. The first concerns the well recognised need to read words in their proper context. The second is directly related to the nature and function of a patent specification. It is a document that is taken as intended to be read through the eyes of the skilled addressee who is equipped with the common general knowledge in the relevant art. The question is what, in an objective sense, such a person would understand the relevant words of the claim to mean. Ultimately, however, it is the claim that must be construed, and it is not permissible to vary or qualify the plain and unambiguous meaning of the claim by reference to the body of the specification: Interlego AG v Toltoys Pty Limited (1973) 130 CLR 461 at 478. 42 A patent specification has a basic structure made up of different parts which have different functions. This is something to which regard must be had when construing a patent specification. In some respects the structure of patent specifications is dictated by the requirements of the Patents Act 1990 (Cth) but in other respects it is simply the product of practices developed over time by those responsible for their drafting. 43 A complete specification must describe the invention fully, including the best method known to the patentee of performing the invention (s 40(2)). It must also end with a claim or claims defining the invention which must be clear and succinct and fairly based on the matter described in the specification (s 40(3)). And the claim or claims must relate to a single invention only (s 40(4)). 44 Since a patent specification must include a detailed description of the invention, and the best method known to the inventor of performing the invention, a patent specification will usually contain a detailed description of at least one embodiment of the invention. But provided a claim is fairly based upon matter disclosed in the specification, a claim may define the invention as having fewer integers than are present in an embodiment so described. Equally, the claim may define an invention as having more features than are present in any such embodiment. It is always open to the patentee to introduce such a limitation if he or she so chooses provided that the claim is fairly based on the matter disclosed in the specification. But if such a limitation has been introduced, it cannot be disregarded simply because the patentee could have framed a valid claim without it. 45 A patentee may have good reason for introducing a limitation into a claim. As Lord Hoffman explained in Kirin-Amgen Inc v Hoechst Marion Roussel Ltd (2004) 64 IPR 444 at para [35], a seemingly inexplicable limitation may have been introduced to avoid arguments in relation to prior art. Lord Upjohn made the same point in Rodi & Wienenberger AG v Henry Showell Ltd [1969] RPC 367 at 392: "…some claims may on a superficial reading appear to be unnecessarily circumscribed, but those who have drafted them may have done so in the light of the prior art …". See also the judgment of Dixon J in Walker v Alemite Corporation (1933) 49 CLR 643 at 656 where his Honour quoted the following well known statement of Lord Parker in Fellows v Thomas William Lench Ltd (1917) 34 RPC 45 at 55 who said "[a] claiming clause operates as a disclaimer of what is not specifically claimed and for such disclaimer there may be reasons known to the inventor but not to the Court". 46 Patent specifications often include a general description or summary of the invention which may include a consistory clause. A consistory clause is in the nature of a general description of an invention which is often expressed in terms which mirror the broadest of the claims: Welch Perrin & Co Pty Ltd v Worrell (1961) 106 CLR 588 at 612. Such clauses are not compulsory but are routinely included by those responsible for drafting patent specifications often with a view to providing fair basis for the broadest claim. Whether or not a consistory clause does so will depend upon whether there are other matters disclosed in the body of the specification which show that the invention is narrower than that described in the consistory clause: Lockwood Security Products Pty Ltd v Doric Products Limited (2004) 217 CLR 274 at para [99]. 47 The part of a patent specification which is put forward by the patentee as a general description or summary of the invention may have a significant role to play in the construction of a claim which is open to different interpretations. This is because the general description or summary of the invention will often describe the invention by reference to features that the skilled addressee would understand to be common to all possible embodiments of the invention.

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Claims 47 and 236 of the child patent 51 Claims 47 and 236 of the child patent provide: 47. A sterilization wrap system comprising: an inner wrap sheet having a first peripheral edge, and an outer wrap sheet having a second peripheral edge; wherein at least a portion of the first peripheral edge is aligned with and not joined to a portion of the second peripheral edge; and wherein the inner wrap sheet and outer wrap sheet are joined to one another at one or more points within an area surrounded by the peripheral edges. 236. A sterilization wrap system comprising: an inner wrap sheet and an outer wrap sheet joined to the inner wrap sheet such that the inner wrap sheet and the outer wrap sheet are visually distinguishable as separate sheets. 52 Multigate denies that any of the claims are infringed on the basis that in each case the invention claimed requires that there be two separate sheets which are then joined together. Kimberly-Clark says that the claims are not so limited and that Multigate's construction introduces an impermissible qualification upon the clear words of the claims. Thus, Kimberly-Clark argues that each of the relevant claims encompasses a single sheet which is doubled over to provide inner and outer layers of sterilization wrap. 53 The primary judge, whose decision is reported as Kimberly-Clark Australia Pty Ltd & Anor v Multigate Medical Products Pty Ltd (2010) 89 IPR 330, accepted Multigate's construction. Her Honour found that the words of claim 1 of the grandparent patent refer to a wrap that is comprised of two sheets that have been joined together. Her Honour said at para [50]: The words of the claim refer to a wrap that is comprised of two sheets, "an inner wrap sheet and an outer wrap sheet". It describes the structure of "each sheet". Again the reference to "each sheet" indicates that the reference is two pieces or sheets. This is made abundantly clear by the statement that the sheets are joined together at "a plurality of bond sites" which occupy no more than the specified area "of either of the sheets". To my mind the inference of two pieces of fabric that are initially not connected is inescapable. 54 Her Honour held that this analysis applied equally to claim 19 (and, by implication, dependent claim 25) of the parent patent and claims 47 and 236 of the child patent. Her Honour said at para [54]: … The language of each of these claims leads inexorably to the construction for which the respondent contends. That is that in each case the sterilisation wrap is comprised of fabric sheets that were initially disconnected. 55 It is common ground that Multigate's sterilization wrap consists of a single sheet in the sense that it consists of a single sheet of sterilization wrap which has been folded over to give two layers. If Multigate's construction of the relevant claims is accepted then it follows that none of them is infringed by Multigate's sterilization wrap system.

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The background of the invention 57 The background of the invention is explained in each of the three specifications in identical terms. The specifications state: The present invention is directed to sterilization wrap materials. More particularly, the present invention is directed to multi-plied materials made from individual sheets which are fused together so as to be suitable for use as a sterilization wrap for wrapping surgical instruments and supplies for sterilization and storage in conjunction with surgical procedures and for other applications such as packaging items for bone marrow units. 58 There follows an explanation of the expression "sterilization wrap". Reusable surgical instruments and supplies must be sterilized before they can be reused. To this end surgical instruments (such as clamps, scalpel blade handles and retractors) are placed in instrument trays while other supplies (such as towels, drapes and gowns) are placed in packages. We shall refer to all such items as "surgical supplies". 59 The specifications state that the trays and packages containing surgical supplies are generally wrapped with two sheets of material commonly referred to as a sterilization wrap. After wrapping, they are then sterilized by autoclaving with steam or by ethylene oxide sterilization. They may then be stored and transported as required. However, whenever such a tray or package is handled there is a risk that the sterility of the surgical supplies wrapped inside it might be compromised. The specifications explain: During storage and transfer to the operating room, the wrapped tray may be handled several different times. Each time the wrapped package is handled, there is a potential that the sterile nature of the package contents can be compromised. The two most common ways the wrapped package can be compromised are a tear or other breach of the wrapping material, and wetness or foreign materials identified on the outer wrapper, which would warrant a premature unwrapping. 60 The specifications then describe two common methods of "double wrapping" using sterilization wrap: A primary method of double wrapping is "sequential" in nature in that the package contents are first wrapped by one sheet of sterilization wrap and then wrapped again by another sheet of sterilization wrap. Another method of double wrapping is "simultaneous" in nature in that the package contents are wrapped by two sheets of sterilization wrap at the same time. That is, two sheets of sterilization wrap are aligned one on top of the other, and the item to be wrapped is placed on top of the two sheets, then the item is wrapped by both sheets of material at the same time. 61 There is further discussion of time saving achieved by simultaneous wrapping techniques over sequential wrapping techniques. However, the specifications explain that there are difficulties with simultaneous wrapping techniques: Even though the hospital staff may desire to simultaneously wrap instead of sequentially wrap, the time it takes to set up the outer and inner sheet wrappers and the awkwardness of manipulating loose wrappers during simultaneous wrapping can offset the time savings hoped to be achieved when attempting to move away from sequential wrapping. Consequently, if a product existed which provided the appropriate inner and outer sheet combinations and eliminated the awkwardness of keeping the two sheets together during the package wrapping and opening processes, then a simultaneous packaging system would deliver the benefits desired including time savings and targeted engineered inner and outer sheet performance. 62 The specifications then refer to a number of proprietary sterilization wraps including a product from Baxter Healthcare Corporation called Dualwrap®: … which includes an inner sheet of wet laid paper (cellulose) and a separate outer sheet of spunlaced or hydroentangled pulp/polyester. The inner and outer layers are provided in a stack of loose, unattached sheets in which the inner and outer sheets are alternated. 63 It is against that background that the specifications then identify what is described as a need for a new "sterilization wrap system". They state: Whatever the material is that is being used as sterile wrap, it should be noted that when wrapping two sheets at the same time, it is important that the wrapping materials provide good barrier properties to maintain package sterility and good strength properties so that tearing or other forms of breaching are held to a minimum. If the outer and inner sheets of the double wrap are to have different properties, then it is important that the system be visually identifiable so that the user can determine which wrapper is the outer sheet and which wrapper is the inner sheet. Consequently, there is a need for a new sterilization wrap system that actually reduces the time for packaging and opening and delivers outer and inner sheet engineered performance in a simple identifiable and easy to use fashion. Such attributes are provided by the present invention as will become more apparent upon a further review of the following specification, claims and drawings. 64 Thus, the background to the invention as explained in each of the specifications reveals that the invention is directed to reducing the time taken by hospital staff in the simultaneous wrapping of surgical supplies in inner and outer sheets of sterilization wrap that are resistant to contamination and tearing and ensuring, if the inner and outer wrap sheets are made of different materials, that the sheets are visually distinguishable to the user.

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The grandparent patent's summary of the invention 66 The grandparent patent includes a summary of the invention in the nature of a consistory clause. It includes the following statement which mirrors the language of claim 1 which is the broadest of the 24 claims of the grandparent patent: There is disclosed herein a method of sterilizing an article comprising: providing an article; wrapping the article with a sterilization wrap which comprises an inner wrap sheet and an outer wrap sheet; and exposing the wrapped article to sterilizing conditions for a sufficient time such that the article is sterilized; wherein each sheet comprises a laminate which comprises a first spunbond layer, a meltblown layer and a second spunbound layer and the sheets are joined together at a plurality of bond sites which occupy no more than 50% of the surface area of either of the sheets such that said sheets are visually distinguishable as separate sheets; and wherein at least one pound tensile force is required to separate said joined sheets. Various preferences are then described. The specification continues: Each of the individual sheets can be designed to have particular properties which may be the same or different from the other sheet of the single step sterilization wrap system of the present invention. There follows some further discussion concerning the different types of inner and outer wraps that might be used for the purpose of the invention together with the following caution: In situations where the inner wrap has different design properties than the outer wrap, [it] is important that the end user be able to determine which of the two wraps (inner or outer) should be placed adjacent the item being wrapped and subsequently sterilized. To this end, the inner and outer wraps can be designed so as to be visually distinct from another as by printing of other indicia as well as the use of different colors or shades with respect to the individual sheets of sterilization wrap. 67 Thus, the consistory clause, and other passages appearing in the summary of the invention, refer to "an inner wrap sheet" and "an outer wrap sheet" which may be made of different materials which have different properties in which case they can, and should be, "visually distinguishable as separate sheets". This is significant in that it cannot be suggested that these words describe characteristics of preferred embodiments only.

[28]

The child patent's summary of the invention 71 The summary of the invention appearing in the child patent specification is somewhat different. It is sufficient to refer to the following statements: The present invention provides an improved means for simultaneously wrapping and unwrapping items which must be sterilized prior to use. This is accomplished by bonding or joining two separate sheets of sterilization wrap together at one or more locations to create a single step system wherein the separate sheets are prealigned and joined to one another to facilitate the wrapping process as well as the unwrapping process. As a result, the amount of time needed to wrap and unwrap an item is decreased and the ease of wrapping is improved. In addition, each of the individual sheets of the single step sterilization wrap system can be specifically engineered or designed to impart special or different features to the overall system. The single step sterilization wrap system includes an outer wrap made from a first sterilization sheet which is superposed on an inner wrap made from a second sterilization sheet with each of the sheets being independent of one another and joined to one another at one or more bond sites. The individual inner and outer wraps can be made from a variety of sterilization materials including fibrous materials such as nonwovens and wovens. … Each of the individual sheets can be designed to have particular properties which may be the same or different from the other sheet of the single step sterilization wrap system of the present invention. 72 Thus, the summary of the invention appearing in the child patent also refers to "bonding or joining two separate sheets of sterilization wrap" in a manner which makes the wrapping and unwrapping process easier and less time consuming. Importantly, "each of the individual sheets" can be made from different materials having different properties. The ability to use sheets made from different materials having different properties is clearly held out as an advantage of the invention. This ability is not merely a feature of a preferred embodiment but a key characteristic of the invention as it is most broadly described in the body of the specification.

[34]

Claim 236 of the child patent 86 Claim 236 of the child patent is another product claim. It is certainly the widest of the claims relied upon by Kimberly-Clark. Nevertheless, it also refers to "an inner wrap sheet" and "an outer wrap sheet" joined together such that they are "visually distinguishable as separate sheets." 87 The question is whether this claim, on its proper construction, requires that the sterilization wrap consist of two separate sheets which have been joined together such that they are distinguishable as separate sheets which have been joined together or whether it is sufficient that it be made of a single sheet which merely has that appearance. In our opinion this claim requires that there be separate sheets which have been joined together in such a way that they are visually distinguishable as separate sheets. A single sheet which has been folded over may be said to consist of two layers but in our view it cannot be said to consist of both "an inner wrap sheet" and "an outer wrap sheet" as these expressions are used in claim 236. 88 We should add that Kimberly-Clark emphasised in its submissions that the fact that the inventions the subject of the patents in suit were directed to problems encountered by hospital staff when double wrapping articles for sterilization using two separate sheets of sterilization wrap did not mean that the claims might not be read as extending to the use of a single sheet of sterilization wrap which was folded over. That is certainly true. However, it is not the description of the problem so much as the language of the claims themselves that is most significant to our interpretation of them. In our view each of the relevant claims, read in the context of the specification in which it appears, is limited to arrangements involving the use of two sheets which have been joined together. Whether or not a valid claim that did not include such a limitation might have been included in any of the patents in suit is not a relevant consideration. 89 Similarly, whether or not any of the claims were intended by Kimberly-Clark to be interpreted as encompassing the use of a single sheet of sterilization wrap folded over to provide inner and outer layers is irrelevant to the question of construction which we have to decide. It is conceivable that the invention has been defined as it has to avoid any suggestion that hospital staff who may have used a single sheet which was folded over to double wrap surgical supplies might have anticipated one or more of the relevant claims. We raise this not because it is suggested that this was Kimberly-Clark's intention or that this actually occurred but to illustrate the point made by Lord Hoffman in Kirin-Amgen Inc v Hoechst Marion Roussel Ltd (2004) 64 IPR 444 at para [35] and Lord Upjohn in Rodi & Wienenberger AG v Henry Showell Ltd [1969] RPC 367 at 392 to which we previously referred.

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