EMD Millipore Corporation v Asahi Kasei Medical Co., Ltd - [2022] APO 6

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
EMD Millipore Corporation v Asahi Kasei Medical Co., Ltd. [2022] APO 6

Patent Application: 2015309939
Title:Porous membrane

Patent Applicant:                   Asahi Kasei Medical Co., Ltd.
Opponent:   EMD Millipore Corporation
Delegate:  Dr N. R. Madsen – Deputy Commissioner of Patents
Decision Date:  02 February 2022
Hearing Date:  9 November 2021 via teleconference

Catchwords: PATENTS – section 59 – a porous membrane for virus filtering measured using SEM imagining – grounds of clarity, best method, clear and complete disclosure, support, manner of manufacture, novelty, and inventive step – no grounds made out – opposition unsuccessful – costs apportioned because of amendments filed during opposition, after evidence in support

Representation: Representative of the opponent: Duncan Longstaff of Shelston IP Lawyers Pty Ltd
Patent attorney for the opponent: Shelston IP Pty Ltd

Counsel for the applicant: Craig Smith
Patent attorney for the applicant: Griffith Hack

IP AUSTRALIA
AUSTRALIAN PATENT OFFICE
Patent Application: 2015309939
Title:Porous membrane

Patent Applicant: Asahi Kasei Medical Co., Ltd.
Date of Decision: 02 February 2022
DECISION
The opposition is unsuccessful. No grounds are made out.
I award costs according to schedule 8 against the applicant up to and including the date of advertisement of allowance of the amendment, and award costs against the opponent according to schedule 8 thereafter.
REASONS FOR DECISION
BACKGROUND

This matter relates to patent application 2015309939 in the name of Asahi Kasei Medical Co., Ltd. (the applicant), having an earliest claimed priority date of 25 August 2014. The patent application was examined and advertised as accepted on 28 June 2018. Following this, a notice of opposition was filed on 28 September 2018 by EMD Millipore Corporation (the opponent).
The request for examination was filed on 27 February 2017 and consequently, substantive amendments to the Patents Act brought about by the Intellectual Property Laws Amendment (Raising the Bar) Act 2012 that came into effect on 15 April 2013 apply to the present patent application. Thus, the standard of proof that applies in the present case is the balance of probabilities. Under subsection 60(3A) of the Act, if I am satisfied, on the balance of probabilities, that a ground of opposition to the grant of a patent exists, I may refuse the application.
The parties filed evidence in the matter with material also being filed outside of the normal rounds of evidence in support, answer, and reply. The applicant also took the opportunity to amend their specification after the filing of evidence in support and these amendments were opposed by the opponent. A delegate considered these amendments allowable in the decision of EMD Millipore Corporation v Asahi Kasei Medical Co., Ltd. [2020] APO 39.
At the hearing the opponent pressed grounds of clarity, best method, clear and complete disclosure, support, manner of manufacture, novelty, and inventive step.
THE EVIDENCE
Evidence in support consists of the following:
·A first declaration by Christine Carbrello (Carbrello #1) dated 1 April 2019 with exhibits CMC-1 to CMC-9
·A second declaration by Christine Carbrello (Carbrello #2) dated 1 April 2019 with exhibits CMC-10 and CMC-11
·A first declaration by Andrew Zydney (Zydney #1) dated 28 March 2019 with exhibits AZ-1 and AZ-2
Evidence in answer consists of the following:
·A declaration by Shoichi Ide (Ide #1) dated 30 October 2020 with exhibits SI-1 to SI-4
·A declaration by Hirohide Otobe (Otobe #1) dated 31 October 2020 with exhibits HO-1 to HO-11
Evidence in reply consists of the following:
·A declaration by David Bell (Bell) dated 21 December 2020
·A third declaration by Christine Carbrello (Carbrello #3) dated 18 December 2020 with exhibit CMC-12
·A second declaration by Andrew Zydney (Zydney #2) dated 22 December 2020 with exhibits AZ-3 to AZ-7
Following the filing of evidence in reply, the applicant wrote to the Commissioner informing of their intention to file submissions challenging evidence in reply and also informing of their intention to file further evidence to address matters raised in the evidence in reply. Subsequently, the applicant identified certain parts of the evidence in reply that they considered not properly in reply however any consideration was reserved for my determination as the hearing officer. To this end, the opponent has sought that any evidence that is not properly in reply be considered by the Commissioner under Regulation 5.23, while at the same time the applicant has sought further evidence addressing such matters also be considered under Regulation 5.23. This further evidence of the applicant is as follows:
·A second declaration by Shoichi Ide (Ide #2) dated 5 April 2021 with exhibit SI-5
·A second declaration by Hirohide Otobe (Otobe #2) dated 7 April 2021
·A declaration by Tomoko Hongo-Hirasaki (Hongo-Hirasaki) dated 6 April 2021 with exhibit THH-1
I noted at the hearing that the details of the evidence in reply issues and the additional evidence filed by the applicant did not appear to bear heavily on the opposition as presented. I note this evidence focusses primarily on the general issue as to the accuracy and reproducibility of described measurement methods. To the extent that any information was relevant to deciding the matter I committed to inform the parties and provide relevant opportunities to deal with material pursuant to the Act and Regulations. For reference, the relevant legislation for my considerations of further information is Regulation 5.23 which states that the Commissioner may consult a document that is relevant to the opposition, which has not been filed and is available in the Patent Office. In doing so I must provide the parties with opportunity to give evidence or make representations about the document. I note that the threshold for the Commissioner to consider information under regulation 5.23 is high, as stated by the delegate in Merial Limited v Bayer Intellectual Property GmbH [2015] APO 16 at [24]:
"I conclude that a decision under regulation 5.23 must have regard to the nature of the information and whether the information is likely, if not certain, to change the outcome of the opposition in a significant way."
As it happens, nothing in this opposition turned on the nature of evidence in reply, or the evidence filed by the applicant as additional material under regulation 5.23. As such, I need not discuss these matters further at this stage.
SPECIFICATION
The specification discusses that to prevent contamination of viruses in medicines, viruses need to be either removed or inactivated. A method of removing a virus is via membrane filtration. Using a membrane filter, viruses of particular sizes can be filtered from a liquid, with a common virus that is filtered for removal being the parvovirus which has a diameter in the range 18-24 nanometres (nm). The performance of a membrane filter focusses upon safety to ensure effective removal of viruses and prevention of contamination of filtered product by the filter itself (elution). A high efficiency of removal is desired from a filter. Filter performance also focuses upon productivity in terms of the recovery of particles in ranges smaller than the virus. With this in mind, the specification discusses that a problem to be solved by the present invention is:
…to provide a porous membrane by which a useful component can be recovered in a highly efficient manner while suppressing clogging during filtration of a protein solution and from which only a small amount of an eluate is eluted even when an aqueous solution is filtered.
The specification describes the invention as a porous membrane containing both a hydrophobic polymer and a water-insoluble hydrophilic polymer. The specification discusses a range of polymers that may be used to make the filter. Envisaging the thickness of the filter and flow of fluid therethrough, a filter is said to comprise a dense layer downstream of a coarse layer. The sizes of the pores are said to be asymmetric with respect to the depth of the filter, increasing in size from a dense layer to a coarse upstream layer. In the claimed invention, the average size property of the dense layer is said to be 50 nm or smaller, the coarse layer thereby being larger than 50 nm in average pore size. Further parameters are used to define the size properties of the pores within the layers. These properties are: a value of a standard deviation of pore diameters divided by the average pore diameter in the dense layer; a gradient index of the average pore diameter from the dense layer to the coarse layer; and an existence ratio of pores in the dense layer being a ratio of pores of a certain size to total pores in the layer.
At this point it is important to note that significant emphasis is placed by the specification on the measurement of pore sizes using scanning electron microscopy (SEM) and a method known as the ‘perfect circle’ method. Only one figure is provided in the specification, Figure 1, being a result obtained by binarizing (right) a specific SEM image (left) of a cross sectioned membrane filter.
Paragraphs [0038] and [0039] explain the calculation of average pore size at different depths of the membrane filter as follows.
The average pore diameter is calculated by a method using image analysis. Specifically, pore portions and solid portions are subjected to binarization with Imagepro plus manufactured by Media Cybernetics, Inc. The pore portions and the solid portions are discriminated based on brightness, the sections that cannot be discriminated or noise is corrected with a free-hand tool. An edge section that forms a contour of a pore portion and a porous structure observed in the back of a pore portion are discriminated as a pore portion. After the binarization, a pore diameter is calculated from a value of an area per one pore assuming that the shape of the pore is a perfect circle. The calculation is conducted for every pore to calculate an average pore diameter every 1 μm x 2 μm range. It is to be noted that discontinuous pore portions at the ends of the visual fields are also counted.
The porous membrane according to the present embodiments has a dense layer and a coarse layer. A visual field having an average pore diameter of 50 nm or smaller is defined as a dense layer, and a visual field having an average pore diameter of larger than 50 nm is defined as a coarse layer.
Thus, the SEM imaging technique described involves physically cross sectioning a membrane filter and measuring average pore size in 1 μm x 2 μm rectangular areas, at different depths in the filter. As a result, the coarse and dense layers can be defined by this measurement. In measuring the size of pores in particular fields of view it becomes a simple statistical task to measure the standard deviation of pore diameters divided by the average pore diameter in the dense layer. This measure is thus a measure of the spread of pore sizes within the dense layer. Similarly, it is also simple to statistically process the results of this imaging technique to work out the ratio of pores of a certain size in the dense layer. Such a measure is useful in describing the number of small pores for example, in the dense layer.
A parameter that appears to have been devised by the applicant is the gradient index of the average pore diameter from the dense layer to the coarse layer. It is said to be calculated using:
…the first visual field as defined as a dense layer and the second visual field as defined as a coarse layer, the second visual field being adjacent to the first visual field… Specifically, the gradient index of the average pore diameter from a dense layer to a coarse layer can be calculated from expression (1) given below. Gradient index of average pore diameter from dense layer to coarse layer = (average pore diameter of coarse layer (nm) (first visual field) – average pore diameter of dense layer (nm) (second visual field) / 1…
It is indubitable that this is a unique equation. The equation merely subtracts average sizes of two neighbouring fields of view that are, by definition, neighbouring fields representing the transition between dense and coarse layers. This transition appears to be described as the point at which the average size of the pores becomes greater than 50 nm. The fact that the equation is divided by 1 appears to simply represent the idea that the visual fields are neighbouring visual fields of 1 μm width (where the width is the dimension along the depth of the filter). A desired range of this gradient index as discussed in the specification is between 0.5 and 12.0. That is to say, across these neighbouring fields, the difference between the average pore size is in this range. As a simple example, if the average size in the field of view in the coarse layer is 55 nm and the neighbouring dense layer is 50 nm, the value of the index is 5. While one may say this is a curious way to parameterise the size characteristics of the membrane filter, it does appear a useful depiction of the change in average pore size across the layer transition. What is clear at this stage of consideration is that the specification seeks to characterise the embodied filters largely by parameters that may not necessarily be commonly used parameters in the art.
At the hearing there was discussion as to the general nature of the porous membrane filters that are the subject of this application. It was broadly agreed that the manufacture of these membrane filters can create an asymmetric pore size distribution that is a function of the depth of the filter. This asymmetric pore size distribution generally manifests as a smoothly increasing size of pores moving through the filter from the output to input side of the filter. This asymmetry of pore size with changing depth is accompanied by a lateral symmetry of pore sizes at particular depths of the filter. In other words, at a certain depth of the filter in the direction of flow from input to output, the pore size is essentially the same across the cross-sectional area of that depth.
While I will not discuss further at this stage, I note the specification does go into some detail regarding the general methodologies for producing these membrane filters, and various measurements of the effectiveness of operation of the filters. I will discuss these aspects further where necessary in the decision.
The claimed invention
The specification, as amended on 6 June 2019 includes 13 claims. Claim 1 as presented below is the independent claim. The claim is consistent with the discussion of the specification provided above.
A porous membrane containing:
           a hydrophobic polymer;
           and a water-insoluble hydrophilic polymer, the porous membrane having:
a dense layer in a downstream portion of filtration in the membrane said dense layer having an average pore diameter of 50 nm or smaller;
           a coarse layer adjacent to the dense layer at an upstream surface side of filtration in the membrane said coarse layer having an average pore diameter of larger than 50 nm; and
           a gradient asymmetric structure wherein an average pore diameter of fine pores increases from the downstream portion of filtration toward an upstream portion of filtration;
           wherein a value of a standard deviation of pore diameters/the average pore diameter in the dense layer is 0.85 or less;
           wherein a gradient index of the average pore diameter from the dense layer to a coarse layer is 0.5 to 12.0, said gradient index being defined as the difference between the average pore diameter in nm of a visual field of the coarse layer and the average pore diameter in nm of a visual field of the dense layer, said visual fields being adjacent to each other, and said visual fields each being 1 µm in width of the membrane thickness direction;
           wherein an existence ratio of pores of 10 nm diameter or smaller in the dense layer is 8.0% or less, and
           wherein the pore diameters are calculated from binarized scanning electron microscope images of a cross-sectional surface of the membrane.
THE PERSON SKILLED IN THE ART
The specification is to be construed through the eyes of the person skilled in the art being a notionally non-inventive skilled worker aware of the common general knowledge in the relevant field. In Root Quality v Root Control Technologies Pty Ltd [2000] FCA 980; (2000) 49 IPR 225 at [71], Finklestein J held that the skilled addressee would have the following characteristics:
“In Catnic Lord Diplock said (at 242) that skilled addressees are “those likely to have a practical interest in the subject matter of [the] invention”. A variety of people may have that interest. There are those who might wish to make or construct the invention, those who may wish to compound the invention and those who may wish to use the invention.”
It is clear that a skilled addressee will have a practical interest in porous membrane technology with specific experience in preparation of polymeric membranes for filtering viruses, along with expertise in the characterisation of membranes by scanning electron microscopy. All the experts are well equipped to comment as to either, or both, of these two streams of technical knowledge involved in the present invention. Where necessary to give preference to the evidence of one expert over another, I give due consideration, and provide reasoning where required.
THE COMMON GENERAL KNOWLEDGE
In Minnesota Mining & Manufacturing Co v Beiersdorf (Australia) Limited(1980) 144 CLR 253 at page 292, Aickin J. stated:
"The notion of common general knowledge itself involves the use of that which is known or used by those in the relevant trade. It forms the background knowledge and experience which is available to all in the trade in considering the making of new products, or the making of improvements in old, and it must be treated as being used by an individual as a general body of knowledge."
As a starting point, the common general knowledge presented by Professor Zydney in Zydney #1 is largely uncontested. I am satisfied that the evidence has established the following as common general knowledge, these facts serving as a useful basis for understanding the nature of the invention:
·     Use of membranes as virus filters was well established in August 2014 (at [26])
·     It was well known that membranes could filter plasma to separate components such as proteins, monoclonal antibodies, and other therapeutics etc. (Zydney #1 at [28])
·     An important goal of such filters is the recovery of product (Zydney #1 [29])
·     It is desirable to retain as much of the virus as possible (Zydney #1 [30])
·     Products on the market were made out of various polymeric materials, having different pore structure. Pore structures in membrane filters were homogeneous in terms of pore size or highly asymmetric having large pores at an inlet side and smaller pores at an exit side. (Zydney #1 [31])
·     There was not a fundamental understanding of the relationship between structure and performance of homogeneous or asymmetric filters. (Zydney #1 [32])
·     20nm pore sizes at the exit side were useful for virus retention and letting through of proteins or other desirable components. (Zydney #1 [33])
·     Membranes were typically made by a phase inversion process involving a mixture of polymer in solvent and non-solvent. A casting process was used that involves removal of the solvent so that the polymer starts to precipitate around the non-solvent, which itself is ultimately washed away to leave empty pores. Additives could be used to control pore size and morphology. (Zydney #1 [43])
·     In investigating new membranes, experiments are designed that vary the temperature, concentration, and properties of the solvent and non-solvent. (Zydney #1 [45])
·     It is difficult to measure the pore size of a membrane. The important parameter for virus filtration is virus retention, not pore size. Size is determined by what will or will not pass through the membrane. A ‘20 nm’ membrane would be expected to retain 20 nm viruses. (Zydney #1 [57])
·     In order to test a membrane’s pore size, the membrane could be challenged with gold nanoparticles. (Zydney #1 [58])
·     Electron microscopy could have been used to measure pore size, but one had to be careful with this technique if one measures pores size at the surface of a membrane. Retentive parts of a membrane are inside a membrane. Electron microscopy could be used for relative measurements of pore size and allowed for direct measurements to be made of physical dimensions of membrane pores. Zydney #1 [60] and Ide #1 [28]
CLAIM CONSTRUCTION
Section 40: Clarity

While the rules of construction for an Australian patent specification are well summarized in Decor Corp v Dart Industries [1988] FCA 399; 13 IPR 385, the correct application of these rules to the construction of claims was discussed by Bennett J in H Lundbeck A/S v Alphapharm Pty Ltd [2009] FCAFC 70; 81 IPR 228 at [118] – [120]:
"the words in a claim should be read through the eyes of the skilled addressee in the context in which they appear ... while the claims define the monopoly claimed in the words of the patentee's choosing, the specification should be read as a whole ... it is not permissible to read into a claim an additional integer or limitation to vary or qualify the claim by reference to the body of the specification ... terms in the claim which are unclear may be defined or clarified by reference to the body of the specification."
I note that the requirement that the claims are clear is understood to be satisfied if a person could ascertain "whether or not what he proposes to do falls within the ambit of the claim" (Monsanto Co v Commissioner of Patents (1974) 48 ALJR 59). Additionally, Flexible Steel Lacing Company v Beltreco Ltd [2000] FCA 890; (2000) IPR 331 (and cited with approval in Austal Ships Sales Pty Ltd v Stena Rederi Aktiebolag [2008] FCAFC 121; (2008) 77 IPR 229) notes:
“Lack of precise definition in claims is not fatal to their validity, so long as they provide a workable standard suitable to their intended use. The consideration is whether, on any reasonable view, the claim has meaning. In determining this, the expression in question must be understood in a practical, common sense manner.”
From the hearing it was clear that front and centre to the matter, like many cases, is the issue of construction. This was particularly so as the applicant appears to have devised a methodology for analysing and depicting the properties of their porous membrane filter that is not widely practiced in the art. With this in mind, I will first focus upon the construction of the claims and therefore the bounds of the monopoly sought, such that I can most effectively consider the other grounds raised by the opponent. The opponent raises a number of issues of claim construction and clarity. They are summarised in the opponent’s written submissions as follows:
“The claims of the Opposed Application rely on calculation of pore diameters and average pore diameters defined in regions of a membrane from binarized SEM images… the Opposed Application fails to clearly disclose or define the dense layer and coarse layer of the membrane (and the boundary between them) and also fails to clearly disclose or define the methods for SEM image acquisition (for example for parameters such as image resolution, brightness and contrast) and subsequent image manipulation and analysis (using binarization protocol, accounting for image depth, and correction using a freehand tool if necessary)…
… It is immediately apparent that if one skilled analyst could determine that a given membrane infringes the claim scope whereas another skilled could determine that the same membrane does not infringe the claim scope then the scope of the claim is not clearly defined. Skilled analysts each have their own individual subjectivities and, consequently, it is not correct to say that different skilled analysist would necessarily reach the same conclusion. The claims rely on determination of the specified parameters and the element of individual subjectivity is not eliminated by the Opposed Application.”
The boundary between dense and coarse layers… What is a dense layer and what is a coarse layer?
When the porous membrane filter of claim 1 is used, liquid will travel through the filter and pass from the coarse layer to the dense layer, encountering progressively smaller pores on average. This arrival during the filtering process at depths of smaller and smaller pore sizes, is reflected in the language of the claim wherein the membrane filter possesses a gradient asymmetric structure. Having an understanding that there may be progressively smaller pores encountered during filtering, there being no compositional difference in the materials of dense and coarse areas of a filter, it is somewhat counterintuitive prima facie, to be able to identify distinct coarse and dense layers. As I understand it, it is from this starting point that the opponent’s contentions appear to arise as to a lack of clarity regarding dense and coarse layers, and the boundary between them.
In their summary of submissions, the opponent argues that claim 1 provides:
“… no definition or direction as to how either the dense or the coarse layers are to be defined, whether independently or by reference to each other, or in what order, or where the boundary between them should be set. Claim 1 only requires that the dense and coarse layers be ‘adjacent’… Arbitrary decisions as to where to set the boundary, and therefore which layer (or visual field) in which pores in that region are ascribed or attributed, will determine whether the same membrane has both the required dense layer and the required coarse layer.
Accordingly, the meaning of ‘a dense layer in a downstream portion of filtration in the membrane said dense layer having an average pore diameter of 50 nm or smaller” is ambiguous and incapable of being reconciled within claim 1 of the Opposed Application.”
In the context of this argument the opponent presents three possible constructions aimed at potentially resolving this issue.
First, they argue that a preferable construction is that the average pore diameter of the dense layer, as a whole, is 50 nm or smaller. I understand this to suggest a construction wherein the average is of the entire dense layer, including all visual fields. In support of this construction the opponent points to the specification where the phrase “all of the visual fields defined as the dense layer” is used in paragraphs [0042], [0043], [0044], and [0045] where parameters such as an existence ratio, porosity, and standard deviation involve a consideration of all visual fields in the dense layer.
Second, they argue a possible construction of the dense layer consisting of visual fields each 1 µm thick, each visual field of the dense layer having an average pore diameter of 50 nm or smaller. They note that this construction would specifically require the visual field at the boundary of the dense layer to be 1 µm thickness and to have an average pore diameter of 50 nm or smaller. Given the structure of these membranes as discussed above, the average diameter at the boundary will be the largest pore size in the dense layer as the pore size decreases with travel to the downstream side of the filter. Reference is made to paragraph [0041] of the specification which notes:
A place appears where a visual field is transferred from a visual field having an average pore diameter of 50 nm or smaller, the visual field defined as the dense layer, to a visual field having an average pore diameter of larger than 50 nm, the visual field defined as the coarse layer.
They submit that the presence of the phrase “a place appears” is vague, and that the sentence seems to confuse “visual field” and “layer”.
Third, they argue that the claim can be construed by limiting the definition of the dense layer to be a single visual field of 1 µm thickness, the coarse layer being immediately adjacent to this dense layer. They point to paragraph [0039] which states:
The porous membrane according to the present embodiments has a dense layer and a coarse layer. A visual field having an average pore diameter of 50 nm or smaller is defined as a dense layer, and a visual filed having an average pore diameter of larger than 50 nm is defined as a coarse layer.
In general, the opponent argues that the most appropriate construction is their first proposed option, and that the claim does not sufficiently define a boundary between dense and coarse layers such that one can determine if they are practicing an invention within or outside the scope of the claim.
In response, the applicant points to the evidence of Mr Ide at [45] of Ide #1 where a figure is provided depicting a membrane filter in the context of the described invention. This figure is also discussed as follows:
“I have prepared a schematic drawing (Figure 1) which illustrates an example of a cross-section of the porous membrane. The drawing indicates the positions of the coarse layer and the dense layer and shows how the coarse layer is at the upstream surface side of filtration and the dense layer is at the downstream portion of filtration. Material to be filtered first passes through the coarse layer and then through the dense layer.”
The applicant refers to this understanding in pointing to the specification at paragraph [0037] which is said to discuss how the dense layer and the coarse layer of the porous membrane are determined. Paragraph [0037] says:
The porous membrane according to the present embodiments has a dense layer in the downstream portion of filtration in the membrane, and a gradient asymmetric structure in which the average pore diameter of fine pores increases from the downstream portion of filtration in the membrane toward the upstream portion of filtration, and a gradient index of the average pore diameter from the dense layer to the coarse layer of 0.5 to 12.0.
In the present embodiments, the dense layer and coarse layer of the porous membrane are determined by taking images of the cross-sectional surface of a membrane with a scanning electron microscope (SEM). For example, a visual field is set horizontally to the membrane thickness direction at an arbitrary portion of the cross-sectional surface of the membrane with 50,000 magnifications. After taking the image of the one visual field that is set, the visual field for taking an image is moved horizontally to the membrane thickness direction and then the image of the next visual field is taken. By repeating the operation of taking an image, photographs of the cross-sectional surface of the membrane are taken without any space, and the photographs thus obtained are connected to obtain one photograph of the cross-sectional surface of the membrane. In this photograph of the cross-sectional surface, the average pore diameter in a range of (2 μm a perpendicular direction to the membrane thickness direction) x (1 μm from the downstream surface of filtration toward the upstream surface side of filtration in the membrane thickness direction) is calculated every one micrometer from the downstream surface of filtration toward the upstream surface side of filtration.
The applicant then refers to paragraph [0039] indicating that this section of the specification explains that if a visual field has an average pore diameter of 50 nm or less, it is part of the dense layer, and visual fields having an average pore diameter of more than 50 nm form the coarse layer. The precise words found in [0039] are again repeated below:
A visual field having an average pore diameter of 50 nm or smaller is defined as a dense layer, and a visual field having an average pore diameter of larger than 50 nm is defined as a coarse layer.
At this point I note that the wording of the applicant does not precisely match the text of paragraph [0039] in that one can suggest that a single visual field is suggested by paragraph [0039] to define the entire dense or coarse layer. However, further explanation is provided in paragraph [0091] of the specification where the calculation formulating the boundary between layers is discussed:
… the calculation was conducted for every 2 μm x 1 μm range. A range where the average pore diameter was 50 nm or smaller was defined as a dense layer, and a range where the average pore diameter was larger than 50 nm was defined as a coarse layer.
Thus, the applicant submits that each visual field in the dense layer has an average pore diameter of 50 nm or smaller, and this is consistent with paragraphs [0042], [0043], [0044], and [0045] which uses the phrase “all of the visual fields defined as the dense layer”. These paragraphs use an average of pore diameters across all of the fields of view in the dense layer to calculate further parameters that are defined in the specification. In doing so, I understand the applicant to present the position that the boundary between coarse and dense layers is sufficiently clear in the context that the layers are claimed to be adjacent, and that adjacent 1 µm wide fields of view at the boundary meet the criteria of being greater than 50 nm in the coarse layer, the neighbouring field of view in the dense layer being 50 nm or less. Since the pore size decreases with downstream flow, each field of view approaching the downstream side should have an average pore size of less than or equal to 50 nm.
At the outset of this exercise of construction of the features related to the definition of the layers in the claim, I made it clear that there was prima facie, some difficulty in understanding when a dense layer ended and when a coarse layer began. This is because there is no precise physically structured boundary defining the layers in the claim. However, the specification appears to lay out a prescriptive formulation for understanding the physical construction of the membrane pore sizes and in particular, the use of terminology relating to layers in an otherwise continuously varying pore structure. The features of a dense layer and coarse layer with the claimed size ranges appear to acquire meaning as set forth in the description. In this regard, I agree that Figure 1 provided by Mr Ide is a fair representation of the dense and coarse layer structure defined by claim 1. A dense layer of 50 nm or less only has clear meaning when the size 50 nm or less in the claim, for a 1 μm wide visual field, is used to define one side of the boundary, with an adjacent visual field of a coarse layer being greater than 50 nm. Such a construction fits neatly with other key elements of claim 1 wherein a gradient index is defined with respect to adjacent 1 μm visual fields of view of coarse and dense layers.
With reference to the opponent’s proposed constructions of the relevant features I make the following comments.
First, I comment on the opponent’s construction that the reference to the dense layer having an average pore size of 50 nm or smaller is a reference to the average of the entire dense layer. While this might superficially seem to be specified in the claims, put simply, I do not see this construction as being supported by the whole of the specification in view of the constructional issues noted above. Nowhere in the specification is a dense layer defined in this manner. While further parameters are calculated on the basis of “all the visual fields defined as the dense layer”, this phrase is consistent with a construction wherein the dense layer and its boundary are defined by the 1 μm visual fields measured from the downstream surface that are within the claimed size range, each of these visual fields being used to calculate further parameters. On my reading of the specification, it is in this light of 1 μm incremental visual fields measured from a downstream surface that a dense layer has useful meaning. This appears to be the only meaning suggested by the body of the specification that assists in the construction of the arrangement of the dense and coarse layers, and definition of the boundary there between.
The second construction put forward by the opponent appears most consistent with that of the applicant. The opponent contended for a construction wherein the average pore diameter in visual fields of 1 μm on either side of the boundary between layers was defined in the numerical manner claimed. I do not believe that the phrase “a place appears” renders any vagueness on the claim as this phrase is defined with respect to the numerical parameters of the claim involving 50 nm. I accept paragraphs [0039] and [0041] appear to have linguistic difficulty in using the terminology “visual field defined as the dense/coarse layer”. However, this difficulty appears easily resolved by considering paragraphs [0037] and [0091] which, similarly to the evidence of Mr Ide, show that dense/coarse layer comprises visual fields, a single visual field itself not necessarily defining a layer. Reading the specification as a whole it is clear that the intention is for the dense layer to be defined by a series of 1 µm visual fields that may include a single 1 µm visual field, but may also include more. Paragraph [0059], for example, refers to a dense layer thickness of 1 - 8 µm, more preferably 2 - 6 µm.
Thirdly, the opponent seeks to equate a visual field with a layer, thus defining a dense layer as 1 μm thick. As above, considering the specification as a whole, it is clear to me that this is not the intention of the prescription of dense and coarse layers. One cannot overlook paragraphs [0037] and [0091] in arriving at an understanding that is reflected by the figure and discussion provided by Mr Ide. I also make reference to paragraph [0093] which states that the thickness of a dense layer was determined as the number of ranges showing an average pore diameter of 50 nm or smaller x 1 (μm). I see no evidence identified by the opponent of difficulty construing this feature that is responsive to evidence of Mr Ide.
In summary, while on its face the claim appears to present some difficulty in identifying the characteristics and boundary between dense and coarse layer, I consider it appropriate to resort to the specification to give the intended meaning to the concept claimed in the form of dense and coarse layers identified with respect to 50 nm average pore diameter. The dense layer is a layer that is defined in the specification by 1 μm increments from the downstream side of a membrane, having a thickness equal to the number of 1 μm visual fields that are 50 nm or less. The coarse layer is thus the adjacent layer having 1 μm visual fields of more than 50 nm. I consider this aspect of the claim is clear.
A Perfect Circle
The opponent notes that the use of the “perfect circle” method is not an explicitly claimed feature, also identifying that no other methods are disclosed in the specification. They discuss that other SEM based methods are available for calculating the size of pores (Otobe #1 at [28]) such as Euclidean distance mapping (EDM) (Carbrello #1 at [34]). In this regard, the opponent argues that EDM and the perfect circle method cannot be expected to give the same results and thus the parameters in the claim are unclear. To briefly summarise the applicant’s response, I note that they argue that while a feature may not be present in a claim explicitly, a patent application may provide a dictionary meaning to a term.
Both parties articulate that the perfect circle method is a rigorous and reproducible measurement involving calculation of the area of a pore and then generating a perfect circle having the same area. It is from this equivalent perfect circle that a diameter is calculated which is defined as the pore size (Otobe #1 at [28] and Zydney #2 at [24]). This is different from a Euclidean Distance Mapping procedure which is described in Exhibit CMC-8 of Carbrello #1 (being a paper entitled ‘Probing pore structure of virus filters using scanning electron microscopy with gold nanoparticles’ by H Nazem-Bokaee et. al.):
A high resolution (4096×3536 pixels) image was obtained by SEM and converted to a binary image map using standardized image analysis, rendering the pore area as white and the polymer as black. The binary image was then subdivided into smaller image strips at different positions through the thickness of the cross section. Each binary strip was then used to create a “skeleton image”, representing the mid-line of each binary feature, and a Euclidean Distance Map (EDM), with the latter created by assigning each pixel a gray level equivalent to its distance from the feature's edge. The edge was assigned a gray level of zero, with the next pixel a gray level of one, and so on until the center of the feature is reached. The two images were mathematically combined using a logical AND operation, resulting in a Skeletonized Distance Map (SDM). The SDM represents the actual radii measurements in pixels of each feature within the image. This gray level data was exported to Excel and used to evaluate the pore size as a function of the pixel distance. The process was repeated for each binary strip to construct a plot of the mean pore radius versus the cross sectional position in the membrane.

Accordingly, I accept that different measurement techniques will likely produce differing results for measurements of pore size. With this in mind, I consider it reasonable to again turn to the specification to understand the context in which the invention is described. As I have referred to above, the specification essentially defines the nature of a dense and coarse layer in the context of the invention. Paragraphs [0038] and [0091] are particularly precise in stating that the perfect circle method is used to calculate an average pore diameter. Paragraph [0038] notes:
The average pore diameter is calculated by a method using image analysis… After the binarization, a pore diameter is calculated from a value of an area per one pore assuming that the shape of the pore is a perfect circle.
Paragraph [0091] also states:
After the binarization, a pore diameter was calculated regarding continuous sections as one pore and assuming a value of an area of one pore to be a value of an area of a perfect circle… A range where the average pore diameter was 50 nm or smaller was defined as a dense layer, and a range where the average pore diameter was larger than 50 nm was defined as a coarse layer.
In a similar way to the specification defining the dense and coarse layers in the manner well depicted in Figure 1 of Ide #1, I am satisfied that the specification also defines the average pore diameter measurements of the specification and thereby the dense and coarse layers, only in the context of the perfect circle method. On this basis, I consider that the perfect circle method inherently provides limitation to the claim, being a limitation wrapped up in the definition of dense and coarse layers present in claim 1, accordingly prescribed by the specification. Reading the specification as a whole, this is a reasonably inferable construction that resolves any potential ambiguity. I also note similar was said in the evidence of the applicant where Mr Otobe noted “a person working in the area of SEM who read the claims of the opposed application would understand from the specification that a particular method is to be used, which is the perfect circle method” (Otobe #1 at [57]). I note Mr Otobe is a skilled microscopist with many years’ experience working with SEM techniques relevant to the present invention (Otobe #1 at [4]-[12]). I could not find evidence from the opponent to refute Mr Otobe’s particular observation.
Thus, I find the claim clear in being limited to the perfect circle method.
Sample preparation
The opponent submits that the claimed invention is not clear in relation to the feature wherein the pore diameters are calculated from binarized scanning electron microscope images of a cross-sectional surface of the membrane, on the basis that the specification and the claimed invention does not identify how the sample is prepared. They argue this is a critical step to defining the boundary of the claim such that one can determine whether a chosen membrane falls within or outside of scope of the claimed invention. Reference is made by the opponent to submissions under the ground of best method where it was further noted that the specification contained no information as to how the membrane was prepared and “fractured” or “cut” such that a cross sectional image could be taken of the membrane.
The opponent’s argument is best supported by evidence of Zydney #1 which essentially notes at [117] that cutting a sample can be difficult and can result in artefacts that can affect the results. However, he also notes that minimisation of artefacts using techniques involving freezing can be performed.
I see no basis to consider the known challenges of preparing a sample as rendering this element of the claimed invention unclear. The feature simply requires calculation of pore sizes from cross sectional SEM images. The person skilled in the art would appear to be well equipped with objectively standard techniques for workably accurate cross sectional sample preparation. This aspect of the claim is clear.
Pore Diameter Measurement – SEM operating conditions
The opponent submits broadly that the features related to the acquisition of SEM images and subsequent image manipulation and analysis of SEM images, for the purposes of calculating pore diameter, are broad and ambiguous. Relevant arguments are largely presented under the ground of best method; however, the general proposition is that absent any specific details in the claims for settings such as image resolution, brightness, contrast, energy of electrons, and image depth, the scope of the claims is unclear because of an inherent lack of consistency and reproducibility. Each of these settings can be considered as operating conditions for image generation using an SEM. The opponent points out that the measured sizes for pores appears sensitive to grey scale image quality noting the evidence of Carbrello #2 at [24] which states:
“Without the knowledge of the conditions used to acquire the image, or to standardize it, a skilled person would not know the correct starting point for the next step of the process, which is processing the image. For example, the brightness and contrast of an image will influence how it is processed.”
Similar was said in Bell #1 at [24]:
“If the brightness and contrast levels selected by the operator resulted in a compressed histogram and the magnification selected was lower than necessary, this could result in a cumulative error. Therefore, it is important to know at least some of the starting conditions, though a skilled microscopist could make an educated guess.”
I interpret the overall thrust of the opponent’s submissions regarding these operating parameters to be that while a skilled microscopist could reproduce the necessary accuracy, because of the lack of specification of parameters, different microscopists may be inconsistent with each other. In response, the applicant makes the following general submission regarding these operating conditions:
“… a skilled person, when provided with the Application, would be able to … select appropriate image acquisition conditions … so as to reliably characterise the fine pore structure of the membrane using SEM.”
I do not consider that the evidence provided by the opponent is sufficient to render the claims unclear regarding the lack of specification of necessary operating parameters of an SEM. As pointed out by the applicant, there is no evidence of significant errors arising in real world situations where skilled scanning electron microscopists are asked to take accurate images to be used in the context of the present invention. I consider that skilled microscopists could at least be expected to have a common understanding of operating parameters that should be applied to create reproduceable and useful images of structures of the scale of the present invention. Absent any evidence of actual ambiguities arising from skilled operation at different parameters, the claims provide an instruction to use SEM imaging, and I do not consider the opponent has discharged their onus to prove that this instruction is not reasonably workable.
Pore Diameter Measurement – Binarization
The opponent alleges that claim 1 fails to clearly define the binarization thresholding process used in calculating pore diameter. More specifically, the opponent points to evidence of Zydney #1 at [125] and [126] which note:
“…depending on how those threshold values are set, one can get very different pore sizes outputs… If the same SEM picture was given to different people, they would get different numbers. Also, data for an infringing membrane could potentially be reinterpreted in order for the result of the pore size calculation for the infringing membrane to be outside the claimed range.”
“The opposed application is very vague as to how binarization is conducted. Even following the opposed application, one would probably get different results with another SEM instrument because the settings are a little bit different.”
I do not consider this evidence demonstrates that the claimed invention is not workably clear. At best this evidence shows that pore sizes might be different due to the setting of the “black/white” binarization threshold in an image, but similarly to the SEM operating conditions, no real-world lack of workability is shown at this point.
The opponent continues by pointing to evidence in Carbrello #2 presenting results of experiments conducted by the opponent’s experts that demonstrate the effect of changing the binarization threshold level on pore size measurements. These experiments show that for image histograms that necessarily depict grey scale data, due to a lack of definitive distinction between grey levels of pore space and polymer, the threshold may somewhat arbitrarily be chosen. This is said to give rise to a lack of clarity. Specifically, at [34] and [35] of Carbrello #2 it is said:
“It is clear in my view that none of the thresholds is apparently inappropriate or wrong. All of these choices of threshold could be seen as very reasonable to a skilled person.”
“…relatively minor changes in the threshold level can change the measurement by breaking up what may normally be considered a single pore when the threshold is low or connecting otherwise separate features when the threshold is high.”
The evidence of the opponent demonstrates significant variance in calculated pore size as a function of a particular change in binarization threshold. However, this point alone is not sufficient to render the claim unclear. It must be the case, for the claim to be unclear, that a skilled addressee would not have a workable standard for binarization to apply to the images generated by skilled microscopists.
Responding to the evidence of the opponent the applicant points to the Otobe #1 declaration and notes that a skilled operator would be able to prepare a suitably flat membrane section, select appropriate conditions and acquire a good SEM image suitable for binarization (at [23]-[28]). In particular, Mr Otobe states that when samples are appropriately prepared applying the imaging skills of the skilled addressee “it’s quite straightforward to identify pixels that belong to the pore or the polymer”. Mr Otobe also notes that SEM images used by Carbrello #2 were of too poor quality to perform the relevant tasks ([71]-[72]), and reiterated that the influence of the binarization threshold is minimal if the surface of the sectioned membrane is flat ([69]). The applicant also points to the experiments in Carbrello #2 and the nature of the work conducted recognising that Ms Carbrello’s work “was not working towards a pore size measurement, rather a series of experiments to show the effect of the binarization threshold” (Carbrello #2 at [31]).
I am inclined to favour the submissions of the applicant. The evidence falls short of demonstrating that a skilled microscopist, armed with the goal of a realistic measure of pore size using the claimed method, would be incapable of reasonably accurately and reproducibly measuring the pore size. While I do not doubt that there is a lack of perfectly precise definition in the specification to guide a skilled person, the evidence fails to show that there is no sensibly applicable point at which to define a binarization threshold given skilled generation of SEM images, such that there would be a significant impact upon measured pore size. Applying best practice sample preparation and imaging techniques would appear to lead to straight forward determination of transitions of pixels from pore to polymer. In this vein, any number of measurements of parameters in the real world necessarily contain inherent imperfections that do not detract from workable usefulness or repeatability. Thus, I find claim 1 clear in this regard.
Pore Diameter Measurement – Freehand tool
The opponent noted that while not claimed, the use of a freehand tool is identified in the description and cannot be ignored, arguing that individual subjectivity plays a part in the use of a freehand tool. They argue the claims do not refer to a freehand tool, the optional use of which must therefore be covered by the binarization process of claim 1. They add that because the application is unclear as to how to use the freehand tool, individual subjectivity comes into play and thus pore diameters are not precisely determinable.
As pointed out by the applicant, it is understood that a freehand tool is a tool available as part of commonly used imaging software and use of such a tool is part of the ordinary skillset of a person conducting SEM image analysis (Otobe #1 at [38]). I accept a skilled microscopist applying their commonly held best practice imaging and analysis knowledge would use a freehand tool to correct for identifiable image defects. Similarly to my previous discussions, I do not consider this element of the described invention renders the claims unclear.
Pore Diameter Measurement – Individual Subjectivity
Arguments presented by the opponent regarding issues of individual subjectivity point to Carbrello #2 at [34] which I have already discussed above in relation to the binarization threshold, fail to demonstrate a lack of clarity for the same reasons. Further reference is made by the opponent to Carbrello #2 at [40] which states:
“A skilled person would try to adjust the darkness and contrast to obtain what they believed was a realistic picture of the membrane and a reasonable approximation of binarizations but, nevertheless, there can be significant variations between individuals and under different circumstances (sic). Without details of the acquisition and binarization there is simply no way to provide a reproducible, absolute value.”
It would seem to be the case that a skilled microscopist may not necessarily use exactly the same settings and, in the hands of different operators, SEM imaging under subjective operation may prevail to an extent. However, there is no evidence that quantifies the magnitude of these potential subjectivities of different skilled microscopists to the extent that I can be satisfied that the claims are not workably clear. Precise, absolute, exactly matching parameters and measurements across different skilled microscopists are not necessarily required for the claim to be clear. I again refer to Otobe #1 where he states at [67]-[69]:
“… the skilled microscopists would be able to select suitable brightness and contrast to perform measurements… in my experience, the influence of threshold level is minimal if the surface of the sectioned membrane is flat.”
The courts have said that it is acceptable if there is minor uncertainty at the edges of a claim. In particular in Glaverbel SA v British Coal Corp [1994] RPC 443 at [495] it is noted:
"The court will give little weight to puzzles which may arise 'at the edge of the claim' if those puzzles would not, as a practical matter, cause difficulty for the skilled addressee or manufacturer wishing to satisfy himself that what he proposes to do will not infringe that patent."
With this in mind, I consider that the evidence fails to establish that there would be difficulty for a skilled addressee, applying their own personal practical knowledge to the task of SEM operation and pore size measurement, in determining if they infringe. The opponent’s case is speculative, and not substantiated.
Pore Diameter Measurement – Limitations of SEM
The opponent also argues that inherent limitations of SEM imaging create ambiguity. They point to evidence of Zydney #1 which states that measuring pore size is not straight forward and that the SEM technique is not very useful for quantitative measurements. They suggest that attempting to use SEM measurements to distinguish very small values such as 0.5 nm is asking more of the technique than it is capable of.
Again, this argument is speculative. I note that the number values described and claimed relate to average pore sizes over necessarily statistically significant numbers of pores, and not absolute measurements of individual pores. As above, while the specification does not provide precise instruction, the evidence does not establish that the claims are not defined to a workable standard.
Average Pore Diameter
The opponent argues that the absence of a requirement in the claims to take into account every pore in an area of 1 µm x 2 µm results in a lack of clarity. They argue that differences arising from individual subjectivities will not average out over a statistically significant pore sample size because errors will be systematic. This argument is addressed in a similar manner to the issues above. To this extent, the evidence does not demonstrate significant subjective biases and errors arising from the use of slightly different parameters and tools by skilled microscopists such that average pore sizes cannot be reproducibly measured.
Gradient Index
The opponent argues that the gradient index of claim 1 lacks clarity because it is reliant on SEM image acquisition and interpretation, referring essentially to the range of issues I have already discussed above. For reasons provided above, I do not consider this feature gives rise to a lack of clarity.
Bubble point measurement using hexafluoroethylene
Claim 7 is directed towards the porous membrane according to claim 1, wherein a bubble point is 1.40 to 1.80. The opponent submits that the bubble point depends on the fluid used to measure it and paragraph [0095] of the description describes measurement of the bubble point using hexafluoroethylene. They note though that hexafluoroethylene does not exist, and with it not being immediately obvious what was intended instead of this fluid, claim 7 is unclear.
The applicant responded by noting that a skilled person would understand that the reference to this non-existent fluid is erroneous since its structure in implausible. They note that while not referred to the specification, “HFE” or “hydrofluoroether” is instead used for bubble point determination and the skilled addressee would use that instead, and thus can readily determine whether a given membrane has a bubble point within the range of claim 7.
I accept the submission of the applicant. The evidence does not suggest that a skilled addressee could not give clear meaning to the claim.
Section 40 (BEST METHOD/Disclosure/Support)
Having found the claims clear, I now turn to further issues raised by the opponent under section 40.
Best Method
To satisfy section 40(2)(aa), the specification must include the best method of performing the invention. In American Cyanamid Company v Ethicon Limited [1979] RPC 215 at page 269, it was stated:
"The Act is intending to protect the public against a patentee who deliberately keeps to himself something novel and not previously published which he knows of or has found out gives the best results, with a view to getting the benefit of a monopoly without giving to the public the corresponding consideration of knowledge of the best method of performing the invention."
Consequently, even if a manner of performing an invention is self-evident, applicants are nevertheless required to set out the best method of performing the invention known to them. The best method requirement is assessed on the basis of the applicant’s knowledge at the time of filing the complete specification (Rescare Ltd. v Anaesthetic Supplies Pty. Ltd., 25 IPR 119).
The opponent takes two general avenues of argument as to an attack under the best method requirement. First, they argue that the application fails to describe the best method for making the claimed membrane, as details of important variables are missing from the examples and other parts of the specification. Secondly, they argue with respect to the calculation of pore diameters and average pore diameters calculated from binarized SEM images, that there is no best method of SEM image acquisition disclosed. Reference is made by the opponent to claimed elements and concepts in alignment with the discussions above in relation to claim construction to the extent that it is said that the specification fails to disclose key parameters and as such, important details of the best method have been withheld.

In relation to the second avenue, the applicant submits that the attack is focussed on issues relevant to clarity and are addressed in that context. I agree with the applicant as the nature of the invention is not in any improvement or modification to existing SEM imaging or image processing techniques. The invention is the creation of porous membrane filters with specific physical properties. While the physical properties are defined in a certain manner in the present invention, any act that the applicant is alleged to have performed in relation to keeping to themselves techniques that give the best results must focus upon the creation of membranes that are effective in removing viruses while having useful resistance to clogging. While the opponent generally touches on this concept in their first avenue of attack, their submissions go no further. As pointed out by the applicant:
“The claims of the Application are directed to products, namely porous membranes.
The Application provides detailed discussion in respect of the example membranes, i.e. Examples 1-14, at paragraphs [0089]- [0124]. This includes detailed disclosure regarding how to prepare those Example membranes, at paragraphs [0100]-[0113].
In terms of performance in removing virus and resisting clogging, by way of example, the porous membrane of Example 3 has both a high LRV of 5 or more, and a high integrated permeability of immunoglobulin for 180 minutes (kg/m2) value of 16.5.
The specification also provides comprehensive information on how to prepare porous membranes, including discussing suitable materials and how to prepare membranes at paragraphs [0020]-[0036], and [0066]-[0088].
The evidence does not support that there was a better example membrane known to Asahi at the filing date than any of Examples 1-14.”
I agree. When the invention is properly understood as a product defined by the claims, the evidence fails to establish that the applicant knew of a better method of performing the invention at the time of filing of the application than that disclosed in the specification. This ground of opposition fails.
Clear and Complete Disclosure
Section 40(2)(a) of the Act requires that the specification mustdisclose the invention in a manner which is clear enough and complete enough for the invention to be performed by a person skilled in the relevant art. Such enablement must be across the whole width of the claims, without undue burden or the need for further invention.
The provisions of s40(2)(a) were considered in detail by a delegate of the Commissioner in CSR Building Products Limited v United States Gypsum Company [2015] APO 72, who having reviewed several recent UK and EPO decisions and having regard to the guidance they provided, formulated the following test in order to determine whether a specification provides an enabling disclosure as required by section 40(2):
a)   construe the claims to determine the scope of invention as claimed,
b)   construe the description to determine what it discloses to the person skilled in the art, and
c)   decide whether the specification provides an enabling disclosure of all the things that fall within the scope of the claims.
A further decision, Evolva SA [2017] APO 57, was issued by a delegate of the Commissioner where further review of UK and EPO decisions was performed, the delegate expanding the consideration of the third question in that it was considered necessary to determine whether it was plausible that the invention can be worked across the full scope of the claim.
The opponent made three initial avenues of argument regarding this ground. I summarise these as follows:
·     The claims rely on a delineation between coarse and dense layers and that the application fails to clearly and completely disclose how each of these layers is defined.
·     The claims rely on calculation of pore diameters and average pore diameters from binarized SEM images. Drawing on arguments made with respect to earlier grounds, the opponent alleges that the methods described in the application are not consistently reproducible in terms of the image acquisition and subsequent image manipulation.
·     The opponent also submits that there is a lack of qualitative information in the specification regarding the parameters and features discussed earlier in this decision under section 40, and thereby, the application lacks sufficient information for a skilled addressee to achieve the promised benefit.
Each of the issues that arises under these general submissions turns directly to the issue of clarity and claim construction. They are accordingly resolved for reasons already provided. The evidence does not demonstrate that the specification fails to enable the production of all things within the scope of the claims. Instead, the evidence is largely directed at the issue of potential ambiguity in claim scope. In terms of these submissions, there is no evidence of any undue burden or a need for further invention to perform within the scope of the claimed invention.
The opponent provides a more precise submission under this ground in arguing:
“…Examples 1-14 each describe the formation of a membranes of the Opposed Application. Example 1 describes a specific process in some detail, and 2-13 recite variations of that process. Example 2 discloses a change in membrane component; Example 3 discloses a different coating composition; Example 7 discloses an irradiation step; Examples 8 and 11 disclose a different bath temperature; Examples 9 and 10 disclose different spinneret temperatures; and Examples 13 and 14 disclose different membrane dope formulations.
These examples show 14 discrete exemplifications of membranes that fall within the scope of the claims, as shown in Table 1 of the Opposed Application. All 14 examples have the required gradient index between the dense and coarse layers, the required existence ratio, and the required standard deviation as set out in claim 1. All have LRV values of 4 or above, which is required to provide adequate virus filtration.
Comparative Examples 3 and 4 also disclose variants of the process of Example 1, in respect of the coating liquid used.
The membranes of Comparative Examples 3 and 4 both possess the required gradient index between the dense and coarse layers, the required existence ratio and the required value of standard deviation of pore diameters / average pore diameter in the dense layer as set out in claim 1. However, Comparative Examples 3 and 4, are said at [0119] and [0121] to be unsuitable as virus filters. The unsuitability is also reflected by the performance criteria in Table 2 at paragraph [0124].
Thus, on the face of the document, the specification shows at least 14 membranes that meet the claimed parameters and usefully function as viral filters, and 2 membranes that meet the claimed characteristics and do not usefully function as viral filters.”
Importantly as noted by the applicant, this argument is more suited to the ground of utility than s40(2)(a). Regardless they note that comparative example 3 does not fall within claim 1 because the hydrophilic polymer was water soluble. This is correct. They also note that it not clear that comparative example 4 involves the use of a water-insoluble hydrophilic polymer. In this regard comparative example 4 uses a different coating composition to example 1. By nature of being “comparative examples” it would appear reasonable to assume that these examples do not reflect the invention. It is thus clear that this argument of the opponent can go no further.
Finally, the opponent submits along the following lines:
·     The opposed application provides no principle of general application that would enable the skilled person to make a membrane suitable as a virus filter (beyond those exemplified) as opposed to a membrane that was not suitable as a virus filter.
·     The opposed application is wholly silent in relation to how gradient index may be controlled, how the existence ratio may be controlled and how the standard deviation may be controlled.
·     Accordingly, the opponent submits that the opposed application represents an invitation to embark on a research program.
Importantly, the opponent fails to identify any evidence to substantiate the necessity for further invention in the form of a research program, or evidence to show an undue burden that needs to be overcome. In the absence of such evidence, it would appear that in taking into account the common general knowledge, the skilled addressee could perform the full scope of the claimed invention. The opponent has not discharged their onus, and as a result, this ground of opposition also fails.
Support
Section 40(3) of the Act requires that the claim(s) must be supported by matter disclosed in the specification.
Burley J explored the requirement of support in Merck Sharp & Dohme Corporation v Wyeth LLC (No 3) [2020] FCA 1477 (Merck Sharp) at [546]-[547]:

“In CSR Building Products Ltd v United States Gypsum Company [2015] APO 72, Dr S D Barker adopted the summary provided by Aldous J in Schering Biotech at 252 – 253, which has been often followed in the United Kingdom (emphasis added):
...to decide whether the claims are supported by the description it is necessary to ascertain what is the invention which is specified in the claims and then compare that with the invention which has been described in the specification. Thereafter the court’s task is to decide whether the invention in the claims is supported by the description. I do not believe that the mere mention in the specification of features appearing in the claim will necessarily be a sufficient support. The word “support” means more than that and requires the description to be the base which can fairly entitle the patentee to a monopoly of the width claimed.
That approach encapsulates broadly the claim support obligation under s 40(3). To it may be added the requirement that the technical contribution to the art must be ascertained. Where it is a product, it is that which must be supported in the sense that the technical contribution to the art disclosed by the specification must justify the breadth of the monopoly claimed”.
Similarly to section 40(2)(a), in this context the body of the specification must disclose the claimed invention in a way which will enable it to be performed by a person skilled in the art without undue burden, or the need for further invention.
The opponent points to paragraph [0020] of the application which discusses that the porous membranes contain a hydrophobic polymer, or a mixture of two or more hydrophobic polymers, and water-insoluble hydrophilic polymer. They further note that [0034] of the application teaches that the membrane may be obtained by subjecting hydrophilic polymer and hydrophobic polymer to blend membrane forming, arguing that the application omits details of important variables in the blend formation process. The opponent also points to the evidence of Zydney #1 at [95] and [97] where it is stated:
“Regarding blends of hydrophobic and hydrophilic monomers, the ratio of hydrophobic to hydrophilic monomers is very important. This is important not only in terms of the surface properties. The ratio also determines pore size characteristics and morphology of the membrane.”
“It is surprising that the applicant does not provide a quantification of those ratios or any measures of surface chemistry of the membrane as part of the opposed application.”
The opponent also notes that it appears that making small change to the membrane-forming process can significantly impact the membrane’s characteristics and that there is no generalised teaching in the application regarding how to make membranes which fulfil the promise of the invention.
The applicant points out that the terms referred to by the opponent are commonly used in membrane manufacture, and that the use of such materials was well known, and their meaning well understood by skilled persons. They refer to evidence of Prof Zydney where he states that “blending a hydrophobic and hydrophilic polymer as a basis for forming the membrane was well established as of August 2014” (Zydney #1 at [82]). I also note, as pointed out by the applicant, that the specification does provide significant detail as to how to prepare the relevant porous membranes, including suitable materials and how to prepare them (paragraphs [0020]-[0036], [0066]-[0088] and [0091]-[0113] of the specification) and more specifically, how to prepare a blended membrane by way of Example 12.
The applicant also points out that the claimed invention is based on a new approach of identifying a combination of structural features of a membrane that correlate with a useful balance of productivity and safety performance. From this standpoint, it is clear that the invention does not appear to lie in any particular method of producing the relevant porous membranes but the specific combination of physical characteristics of the polymer. It is this combination of characteristics that I consider to be the technical contribution to the art. While there may be some work for a skilled addressee to take the teaching of the specification and identify suitable parameters for the production of porous membranes within the scope of the claim, the evidence does not establish that there would be any particular burden or need for further invention faced in this exercise.

100. The opponent also submits that there is a lack of support arising for reasons analogous to those already discussed under section 40 in relation to the calculation of pore size, noting also that the description only justifies the use of the perfect circle method. I have already addressed these issues in the context of clarity, noting that the perfect circle method is necessarily an element of the claimed invention by way of reasonable construction considering the specification as a whole.

101. Therefore, I find the claimed invention is supported.
MANNER OF MANUFACTURE
102. Schedule 1 of the Patents Act defines "invention" as:
"any manner of new manufacture the subject of letters patent and grant of privilege within section 6 of the Statute of Monopolies, and includes an alleged invention".

103. Subsection 18(1)(a) states:
"an invention is a patentable invention for the purposes of a standard patent if the invention, so far as claimed in any claim is a manner of manufacture within the meaning of section 6 of the Statute of Monopolies."

104. The definition of "invention" in schedule 1 therefore incorporates both the aspect of newness and the aspect of manner of manufacture, whereas sec 18(1)(a) omits reference to the aspect of newness. Nevertheless, in the decision of the High Court in NV Philips Gloeilampenfabrieken v Mirabella International Pty Ltd 32 IPR 449 (Philips) (which was confirmed by Advanced Building Systems Pty Ltd and Anor v Ramset Fasteners (Aust) Pty Ltd (1998) 152 ALR 604; (1998) AIPC 91-40; 40 IPR 243), the majority of the High Court concluded that "newness" was imported into sec 18(1)(a) to the extent that:
“the phrase “manner of manufacture within the meaning of section 6 of the Statute of Monopolies” in s 18(1)(a) should be understood as referring to a process which is a proper subject matter of letters patent according to traditional principles.”

105. Thus, the expression "manner of manufacture" under the 1990 Act has the same meaning and involves the same concepts as the expression "manner of new manufacture" under sec 35(1)(aa) of the 1952 Act. In effect, this gives rise to a concept of “newness” on the face of the specification applicable under section 18(1)(a). This “internal” newness is articulated in Philips as follows:
“…if it is apparent on the face of the specification that the subject matter of the claim is, by reason of absent the necessary quality of inventiveness, not a manner of manufacture for the purposes of the Statute of Monopolies. That does not mean that the threshold requirement of an “alleged invention” corresponds with or renders otiose the more specific requirement of novelty and inventive step (when compared with the prior art base) contained in s 18(1)(b). It simply means that, if it is apparent on the face of the specification that the quality of inventiveness necessary for there to be a proper subject of letters patent under the Statute of Monopolies is absent, one need go no further.”

106. The opponent notes that the invention in claim 1 of the application is:
“…a porous membrane containing a hydrophobic polymer and a water-insoluble hydrophilic polymer, having an asymmetric pore structure in which the pore diameter decreases from the upstream surface through the membrane to the downstream surface, that asymmetric pore structure being (purportedly) defined by particular geometric parameters derived from measurements of pore diameter calculated from binarized SEM images.”

And that the specification contains admissions that, at the priority date:
“…porous membranes containing a hydrophobic polymer and a water-insoluble hydrophilic polymer and having an asymmetric pore structure, had been applied and were known to be useful for filtering viruses from biological products such as fractionated plasma products.”

107. Importantly, it is clear that the specification does not contain any admissions in relation to the values of various claimed parameters and whether they are known or would have been obvious to a person skilled in the art. As pointed out by the applicant, the opponent’s submissions ignore the significance of the particular combination of features of claim 1. It is clear that the specification, on its face, does not make apparent that there is a lack of newness or inventiveness. This ground of opposition fails.
NOVELTY
108. For the purposes of subsection 7(1) of the Patents Act, an invention is to be taken to be novel when compared with the prior art base unless it is not novel in the light of any one of the prior art information. Subsection 7(1) also states that two or more documents can be read as a single piece of prior art information if the relationship between those documents is such that a person skilled in the art would treat them as a single source. Furthermore, prior art information includes a “prior use” constituting information made publicly available before the priority date through the doing of an act.
109. It is well established that the general test for anticipation is the reverse infringement test. The classic formulation of this test is that given by Aickin J in Meyers Taylor Pty Ltd v Vicarr Industries Ltd [1977] HCA 19 at [20]; 137 CLR 228 at [235]:
“The basic test for anticipation or want of novelty is the same as that for infringement and generally one can properly ask oneself whether the alleged anticipation would, if the patent were valid, constitute an infringement.”

110. This test is satisfied if the alleged anticipation discloses all of the essential features of the invention as claimed (Nicaro Holdings Pty Ltd v Martin Engineering Co [1990] FCA 40 at [19]; 16 IPR 545 at [549]). To meet this requirement, the prior art must contain “clear and unmistakable directions to do what the patentee claims to have invented” (The General Tire & Rubber Company v The Firestone Tyre and Rubber Company Limited [1972] RPC 457 at [486]). As per the General Tire case: “A signpost, however clear, upon the road to the patentee’s invention will not suffice. The prior inventor must be clearly shown to have planted his flag at the precise destination before the patentee”.
111. I also note that an alleged anticipation need not explicitly disclose all of the essential features of the claimed invention. In this regard, a disclosure may be implicit as discussed in Bristol-Myers Squibb Company v FH Faulding & Co Ltd [2000] FCA 316; 46 IPR 553 at 576:
“What all authorities contemplate, in our view, is that a prior publication, if it is to destroy novelty, must give a direction or make a recommendation or suggestion which will result, if the skilled reader follows it, in the claimed invention. A direction, recommendation or suggestion may often, of coarse, be implicit in what is described and commonly the only question may be whether the publication describes with sufficient clarity the claimed invention or, in the case of a combination, each integer of it.”

112. The opponent presses its novelty case with a focus to an issue of “parameteritis” with respect to the Viresolve^TM Pro porous membrane, often referred to as the VPro, marketed by the opponent in 2008 and described in patent US 9415353. Importantly I note that the US patent document was published after the priority date of the present application and as such, is not prior art itself. I will leave the question of whether prior use of the VPro membrane is established aside, as the question of novelty of the claimed invention is resolved by merely considering the potential disclosure of the alleged prior use.
113. The alleged prior use, which is aligned with the disclosure of the US patent document, is said to disclose the following features:
a)   a porous membrane containing:
b)   a hydrophobic polymer, and
c)   a water-insoluble hydrophilic polymer, the porous membrane having:
d)   a dense layer in a downstream portion of filtration in the membrane;
e)   a coarse layer adjacent to the dense layer at an upstream surface side of filtration in the membrane;
f)    a gradient asymmetric structure wherein an average pore diameter of fine pores increases from the downstream portion of filtration towards an upstream portion of filtration.

114. This is not substantially disputed by the applicant. In fact, these features appear consistent with the background of the specification and the identification of the common general knowledge by the experts in relation to porous membrane virus filters.
115. What remains to consider are specific features related to average pore diameters of dense and coarse layers, the gradient index, standard deviation, and existence ratio of pores 10 nm or smaller. In summary, it is the opponent’s submission that such features are merely an arbitrary convenience representing a “parameteritis” that achieve no technical effect. More specifically the opponent submits:
“…the gradient index is not a parameter otherwise known in the art and accordingly defies ready comparison with prior art membranes. The criticality of the gradient index is not demonstrated nor explained, no correlation with membrane performance is demonstrated.
The existence ratio is not shown to be a critical parameter. The criticality of the existence ratio is not demonstrated nor explained, no correlation with membrane performance is demonstrated.
The value of standard deviation of pore diameters / average pore diameter in the dense layer is not shown to be a critical parameter. The criticality of the value of standard deviation of pore diameters / average pore diameter in the dense layer is not demonstrated nor explained, no correlation with membrane performance is demonstrated.
The examples and comparative examples present a patchwork of parameters, with variations of gradient index, existence ratio and standard deviation.”

116. As the applicant correctly points out, parameteritis is not a term found in the Patents Act, and it is does not represent a separate ground or requirement that must be met for a claim to be novel. It is relevant to ask whether a claimed feature is essential, and at times a feature that may fall under a label of parameteritis may itself be inessential for the purpose of a novelty consideration. However, in the present case, it is my view that the specification makes clear that the parameters defined in the claim do in fact represent essential features of the invention. They combine to provide a porous membrane filter that realises the technical effect of suppressing clogging during filtration of a protein solution from which only a small amount of an eluate is eluted. I cannot see how the parameters are an arbitrary convenience to the extent that they may be considered inessential to the claimed invention.
117. The opponent, in investigating the porous filter alleged to form the relevant prior use, uses the Euclidian distance mapping method to determine pore size. Furthermore, they make no measurement of the dense layer existence ratio, nor do they determine the standard deviation of pores / average pore diameter in the dense layer. Thus, the evidence fails to establish the necessary presence of all of the essential features of the claimed invention in prior art. I find the claimed invention novel.
INVENTIVE STEP
118. The test for obviousness was provided by Justice Aicken in Wellcome Foundation Ltd v VR Laboratories (Aust) Pty Ltd [1981] HCA 12 at [45]; 148 CLR 262 at 286 as follows:
“The test is whether the hypothetical addressee faced with the same problem would have taken as a matter of routine whatever steps might have led from the prior art to the invention, whether they be the steps of the inventor or not.”

119. The High Court in Aktiebolaget Hässle v Alphapharm Pty Ltd [2002] HCA 59 at [51]- [53];; 212 CLR 411 at [51]-[53] approved this approach, in addition to that taken in Olin Mathieson Chemical Corporation v Biorex Laboratories Ltd [1970] RPC 157 at 187 in which Graham J had posed the question:
“Would the notional research group at the relevant date in all the circumstances directly be led as a matter of course to try [the claimed invention] in the expectation that it might well produce a useful [desired result]?”

120. The usual approach to determining inventive step is the problem-solution approach. Once the problem has been formulated and the common general knowledge and the prior art base has been determined, the question of whether the claimed solution is obvious must be addressed.
The Problem
121. As discussed above in this decision, the problem addressed by the claimed invention can be formulated as follows:
…to provide a porous membrane by which a useful component can be recovered in a highly efficient manner while suppressing clogging during filtration of a protein solution and from which only a small amount of an eluate is eluted even when an aqueous solution is filtered.

Prior Art Base
122. The primary attack by the opponent as to a lack of inventive step is based on common general knowledge alone. The opponent also attacks the claims on the basis of prior use of the VPro membrane and US 9415353, but that attack suffers similar issues discussed above in relation to novelty to the extent that information does not appear to form part of the prior art base. More importantly, the second attack is based on a starting point of the prior art being essentially the same as that for the common general knowledge. Thus, I need only focus on the allegation that the claimed invention is obvious in view of common general knowledge.
Was the invention obvious?
123. I have identified agreed common general knowledge above at [23]. It is clear that the following combination of features in relation to the fine pore structure of a porous membrane has not been demonstrated to be common general knowledge:
·a value of a standard deviation of pore diameters/the average pore diameter in the dense layer which is 0.85 of less
·a gradient index of the average pore diameter from the dense layer to a coarse layer which is 0.5 to 12.0
·an existence ratio of pores of 10 nm diameter or smaller in the dense layer which is 8.0% or less

124. As with their argument with respect to novelty, the opponent alleges that every one of these features is arbitrary, stating that no criticality of any of these parameters has been demonstrated such that they are either meaningless or obvious.
125. The applicant submits that the structure and performance relationships were not well established at the priority date, referring to Ide #1 at [63]. This is confirmed by evidence in Zydney #1 at [32] where Prof Zydney makes similar observations. As identified by the applicant, none of the experts suggested that the provision of a membrane having the pore structural characteristics of claim 1 was common general knowledge. It is the case that Prof Zydney does not consider there to be a reason why he could not make a membrane that would satisfy claim 1 prior to amendment, and this is consistent with the notion that well known techniques would be used to make porous membranes according to the specification.

126. Importantly, the applicant appears to have developed an invention constituted in the identification of a specific combination of parameters that solves the stated problem. They are clearly not arbitrarily selected parameters. Absent evidence to demonstrate that this combination of parameters is well-known, or that the person skilled in the art would be directly led to arrange the claimed combination of physical parameters of the porous membrane in light of the common general knowledge, I cannot consider the invention to lack an inventive step. This ground of opposition also fails.

CONCLUSION
127. I conclude that the claimed invention is clear. Following my construction of the claims, no other grounds of the opposition are made out. The opposition is unsuccessful.
COSTS

The applicant has been successful in defending the application and normally costs would follow the event in being awarded against the opponent. In the present case, amendments were made by the applicant following evidence in support. The amendment materially narrows the claims and, on this basis, it can be said that the opponent has been successful, up to the point the amendments were advertised.
Hence, I will award cost against the applicant up to, and including, the date of advertisement of allowance of the amendment and award costs against the opponent thereafter.
Dr N. R. Madsen
Deputy Commissioner of Patents