W.L. Gore & Associates, Inc. v David Goldfarb

[1986] APO 3

In the Matter of the Patents Act 1952

‑ and ‑

In the Matter of Application No. 493280 for a Patent by W.L. GORE & ASSOCIATES, INC.

‑ and ‑

In the Matter of Opposition thereto under Section 59 by DAVID GOLDFARB.

DECISION OF A SUPERVISING EXAMINER OF PATENTS:
Background
         This is an opposition to the grant of a patent on application No. 493280 entitled "Artificial Prosthetic Devices" by W.L. Gore & Associates, Inc (herein referred to as the GORE application).  The application was lodged on 27 February, 1975 and claimed priority from application No. 457711 lodged in the United States on 2 April, 1974.  The application was advertised as accepted in the Official Journal on 8 June, 1978.  A notice of opposition to the grant was lodged on 7 December, 1978 by David Goldfarb.
         The matter was heard in Melbourne on 13 August, 1985.  Mr. R.C. Macaw of Counsel instructed by Mr. J.A. Waters, patent attorney of Phillips, Ormonde & Fitzpatrick represented the applicant and Dr. J.McL. Emmerson of Counsel instructed by Mr. L.T. Dyson, patent attorney of Edwd. Waters & Sons represented the opponent.
The Specification
         According to the specification the invention relates to artificial prosthetic devices comprising porous, expanded high strength polytetrafluoro‑
ethylene (herein referred to as expanded PTFE).

In particular, the specification states that the invention relates to a method of replacing a part of the vascular system of the body by a bio‑
compatible device which enhances biological tissue growth, the device comprising expanded PTFE possessing a microstructure consisting of nodes interconnected by fibrils wherein the length of substantially all of the fibrils exceeds 5 microns.
         The specification reviews prior art vascular prostheses and notes that these have not been successful because they failed to inhibit the formation of blood clots: it goes on to state that:

"For total success, an artificial arterial prosthesis must provide an open pathway for blood to pass along its entire length and additionally it must not generate embolization of the distal arterial bed.  All prior synthetic polymeric materials exhibit varying degrees of surface thrombogenicity due to activation of plasma coagulation factors leading to fibrin formation."

The solution to the problem of providing a viable substitute for human veins and arteries is described as being a "wholly surprising discovery", thus:

"It is a wholly surprising discovery that when a prosthetic device in the form of a tube is used as an artificial vascular prosthetic, as the healing process proceeds, tissue grows into and through the pores between the fibrils of the tube forming a vascular replacement consisting of a building scaffold or skeleton of the synthetic material which becomes completely surrounded by and filled with new tissue.  The spaces between the fibrils may be very small, perhaps less than one micron. However, the fibroblast cells appear to push aside the fibrils as they penetrate the porous structure, and finally corpuscular blood circulation develops into and throughout the tissue that has invaded the fibrillar structure of the prosthetic.  Thus, the open space between the fibrils, which may constitute 80‑90% of the bulk volume of the prosthetic material, is completely filled by natural living tissue.  It is a wholly surprising discovery and contrary to prior art teachings that, during the healing process and without prior pre‑clotting, such a tube which can be 80‑90% porous will contain blood at arterial pressures.  After healing, blood passage is through what is effectively a new‑tissue tube, the blood coming in contact with the new‑tissue inner surface (intima) of the tube.  Also surprisingly, even prior to healing, this construction of synthetic‑scaffold/new‑tissue prosthetic appears to be the most non‑thombogenic vascular replacement yet known, ..."

The c haracteristics of an ideal prosthesis are known and these are referred to in the specification at page 3, namely:

"As a result of considerable volume of trial and testing of synthetic vascular prostheses, the characteristics of an "ideal" construction have been set forth*, namely:

(1)"absence of toxicity, allergenic potential or other overtly adverse chemical reaction; the biological reactivity of the material per se, over the range of that from Teflon to glass is not a limiting factor in the biological healing of the synthetic vascular prosthesis;

(2)the prosthesis should be durable without significant deterioration of the synthetic yarn upon prolonged implantation.  Nylon, Orlon and Ivalon are disqualified on this account; Dacron, Vinyon‑N and Teflon qualify.  Dacron is preferable because of its superior mechanical handling properties during fabrication and at implantation;

(3)the biological healing porosity should be of the order of 10,000 milliliters of water per minute per sq. cm. fabric at a pressure head of 120mm Hg.  It should be pointed out that no commercially available prosthesis today meets this specification because the limit of a safe implantation from the viewpoint of haemorrhage is in the vicinity of 5000 ml. of water per min. per sq. cm., at a pressure head of 120mm Hg.;

(4)ideally, the material should have a low implant porosity to enable the administration of heparin or other anticoagulant: less than 50cc. per min.  per sq. cm. at a pressure head of 120mm Hg.;

(5)there should be desirable handling properties which facilitate implantation which, therefore, becomes safer:

(a)conformability ("scrunchability") for ease of performance of anastomosis;

(b)linear elasticity is desirable; crimping in our experience is preferable to elastic yarn because with graft shortening the latter is more likely to affect adversely the porosity;

(c)the fabrication should have good pliability and good twist characteristics for traversing flexion creases and subcutaneous and subfascial tunnels without significant mechanical kinking."

* Weslowski, S.A. and J.D. McMahon, "Artificial Arteries", AORN Journal, January, 1968.

The specification then explains that the material used in the invention is porous PTFE, and this material has the property of being chemically and biologically inert to almost all known substances.  As such, it possesses (before tissue invasion) nearly all of the desirable properties of the "ideal" prosthesis, whose properties were described above.
         Other proprietary material such as Teflon and Dacron possess similar properties and have in the past been used as artificial veins and arteries.
         However, after tissue implantation of the porous PTFE prosthesis, tissue invades the structure and forms what is effectively a natural tissue structure.  The specification states that this does not occur with prior art devices.
         Porous PTFE is manufactured by stretching extruded, unsintered poly‑
tetrafluoroethylene.  This material is marketed by Gore under the trade mark GORE‑TEX and is described in Australian Patent Specification 458088.
         The present specification describes that the surprising result of the ingrowth of new tissue into a vascular prothesis only occurs if the fibril length (i.e. the length of the fibrils between nodes) exceeds 5 microns and is less than 1000 microns.  The benefit of this range is expressed in the following terms:

"Within this range and during the healing process, fibro‑

plastic and capillary ingrowth into the prosthetic occur, with uniform neointimal development over the grafts and suture line surfaces."

Above 1000 micron fibril length, mechanical disadvantages can occur in suturing the vascular prosthesis to the tube of the body and blood leakage can become a problem.
         A further problem with vascular prostheses having a fibril length exceeding 1000 microns is that the driving force of the internal blood pressure can cause blood leakage through the walls thereof.
         The preferred range for fibril lengths is stated as being from 20 to 100 microns.
         Four examples are described.  All involve tubular grafts of expanded PTFE having various ranges of fibril length with different values for the parameters of length, diameter, wall thickness, and porosity.
         It is convenient to summarize the examples as follows:

1       4cm       4mm        20‑32mils    0.25‑      5‑100
  0.34 g/cc   microns

2       8‑12cm     3‑5.6mm     20,32,62     0.22‑      3‑150
  mils        0.34g/cc    microns

3       4cm       28‑33mm     32mils      0.21‑      25‑1000
  0.35g/cc    microns

4       10cm      7.5mm      20mils         ‑       20‑40
  microns

Regarding example 1, two series of experiments were conducted; expected patency rates of 87.5% and 88% respectively were predicted.  Some of the occluded grafts were stated as being due to technical errors in surgery.  Within the fibril length range of 5 to 20 microns, the grafts yielded a 100% patency rate.  Histological examination of all the harvested patent grafts have, according to the results of these series of experiments, "shown transmural fibroblastic and capillary ingrowth with uniform neointimal development over the grafts and suture line surfaces".
         Regarding example 2 the results are summarized as follows:

"Histological examination demonstrated that grafts with fibril length ranging from 20 to 150 microns contain fibro‑

blastic and capillary ingrowth as well as neointimal development throughout the graft's lumen.  Grafts with less than about 7 microns fibril length displayed an absence of fibroblastic and capillary ingrowth with no neointimal development over the graft's internal surface."

Regarding examples 3 and 4, the expected patency rate was 100%.  Histological findings on harvested grafts have (according to the specification) demonstrated both "transmural fibroblastic and capillary ingrowth with uniform neointimal development over the grafts and suture line surfaces".
         The specification ends with six claims, reading as follows:

1. The method of replacing a part of the vascular system of the body by a biocompatible device which enhances biological tissue growth comprising expanded, porous polytetrafluoro‑

   ethylene possessing a microsctructure consisting of nodes interconnected by fibrils, wherein the length of substantially all of said fibrils exceeds 5 microns.

2.The method of claim 1 for replacing a vascular conduit by a tube of expanded, porous polytetrafluoroethylene wherein the length of substantially all of said fibrils exceeds 5 microns.

3.The method of claim 2 wherein the length of substantially all of the said fibrils falls within the range 5‑1000 microns.

4.The method of claim 3 wherein the expanded, porous polytetra‑

fluoroethylene possesses a matrix tensile strength in at least one direction exceeding 7,300 psi.

5.The method of claim 3 wherein the length of substantially all of said fibrils is from 20‑100 microns.

6.The method of claim 4 wherein the length of substantially all of said fibrils is from 20‑100 microns."

Grounds of Opposition
         The grounds of opposition stated in the notice are those available under paragraphs (a), (c)(i), and (i) of sub‑section 59(1) of the Act.  Mr. Macaw indicated at the hearing that the opponent was also relying on paragraph (e).
Section 40
         Under this heading the opponent raised the following points:

(a)There is no fair basis for a claim to a method; at best the disclosure could support a claim to a prosthetic device.

(b)The claims are not limited to a structure which facilitates invasion by tissue of a character and extent necessary to secure a uniform neointimal.

(c)The invention claimed is not limited to specific parameters of wall thickness, density, or porosity.

(d)There is no upper limit set to fibril length in claims 1 and 2.

(e)The claims include certain structures which will not actually work as one of the examples refers to a fibril length of 7 microns as not working.

(f)The prosthesis should be limited to a tubular structure because there is no fair basis for something that is not tubular.

(g)The use of the word "porous" in claim 1 was tautological and perhaps unclear.

I do not agree with Mr. Macaw's point (a).  The method is defined, inter alia, by reference to a device.  It is clearly intended, as reference to the examples will show, that the method involves using known surgical techniques to implant the prosthetic device.  The mere fact that no such steps are specified does not, in my opinion, mean that the claims of necessity lack fair basis.  Nevertheless, I believe the claims are not clear in that while purporting to define a method they do not define any method steps except by inference.  On this point, it is interesting to note that the description at page 4 lines 9 to 14 incorrectly represents the invention as a device per se, whereas there are no claims so directed.
         I find it convenient to deal with points (b), (d) and (f) together.
         Basically, these points amount to an allegation that claims 1 and 2 lack fair basis because the promise of the invention is not realized unless the prosthesis is tubular, and the fibril length is between 5 and 1000 microns.
         I find that this argument has merit.  The specification refers to the surprising discovery that when the prosthetic device is in the form of a tube having a fibril length of between 5 to 1000 microns and is used as a vascular prosthesis the advantages of the invention accrue.
         This view of the invention is supported by the description at page 4, lines 15 to 22:

"It is a wholly surprising discovery that when a prosthetic device in the form of a tube is used as an artificial vascular prosthetic, as the healing proceeds, tissue grows into and through the pores between the fibrils of the tube forming a vascular replacement consisting of a building scaffold or skeleton of the synthetic material which becomes completely surrounded by and filled with new tissue";

at page 6 lines 8 to 10:

"In tubular form and in use as a vascular prosthetic, the length of the fibrils 12 exceeds about 5 microns but is less than about 1000 microns";

and at page 7, lines 4 to 11, and lines 15 to 26:

"In accordance with the present invention, it was discovered that porous expanded PTFE gave unexpectedly beneficial results when used as an artificial vascular prosthetic when the fiber (fibril) length in such devices was between 5 and 1000 microns.  Within this range and during the healing process, fibroblastic and capillary ingrowth into the prosthetic occur, with uniform neointimal development over the grafts and suture line surfaces."

......................

"Above about 1000 micron fibril length, mechanical disadvantages can occur in suturing the vascular graft to the host tube, and blood leakage can become a problem.  This upper limiting range of fibril length is difficult to define quantitatively, however, and depends to some extent upon the skill of the surgeon administering the graft.  Blood leakage can also occur in vascular devices which have long fibrils (exceeding 1000 microns) caused by the driving force of the internal blood pressure.  In the range of 5 to 1000 micron fibril length, however, the prosthetics of this invention both contain the blood and simultaneously allow tissue ingrowth."

Dr. Emmerson, for the applicant, argued that the description at page 11, line 26 to page 12, line 3 provides fair basis for claims 1 and 2.
         The specification at this point reads as follows:

"Also the fibril‑node structure of these prosthetics are generally suitable for other than vascular applications.  The tissue ingrowth has been shown to occur in skin grafts and in membranes implanted subcutaneously.  Such grafts need not contain blood under the driving force of arterial pressure, and therefore the upper limit of fibril length for such applications is greater than 1000 microns, and is limited only by mechanical considerations."

In my opinion this paragraph is irrelevant as the claims are directed to a method of replacing a part of the vascular system of the body, and the description to which I have referred above clearly sets out the conditions required to do this successfully.
         Consequently, I take the view that Mr. Macaw is correct in this matter.
         Point (c) is related to Mr. Macaw's submission of obtaining.  He argued that the claims are not fairly based because they do not refer to the parameters of wall thickness, density and porosity.  It is these features that, according to his argument, are necessary for the promise of the invention to be fulfilled.  It is these features that are alleged to form part of the invention that was obtained from Dr. Goldfarb.
         Regarding porosity, the only reference in the specification to this feature occurs in relation to the nature of the expanded PTFE.
         I can find no basis in the specification for the submission that the invention involves considerations of wall thickness, density or porosity as essential elements.  Although the examples refer directly to wall thickness or density or indirectly to porosity (expanded PTFE is porous), in my view these parameters form the experimental backdrop upon which the importance of the fibril length can be seen.  If in fact, as Mr. Macaw seems to suggest, these particular features are essential considerations in the successful performance of the method of the invention as claimed, the problem is not one of fair basis but of utility.
         Part (e) is a reference to example 2 which states that:

"Grafts with less than about 7 microns fibril length displayed an absence of fibroblastic and capillary ingrowth with no neointimal development over the graft's internal surface."

Although this is at variance with the stated lower limit of 5 microns for fibril length, I agree with Dr. Emmerson's submission that these particular grafts were just part of the experimental background and do not conflict in any real sense with the general statement of the invention or with the results discussed in this and the other example.
         I do not believe regarding point (g) that the use of "porous" in claim 1 is tautological or that it renders the claim unclear; it is a term that refers to one of the characteristics of the material which is more specifically defined in the succeeding part of the claim by reference to the microstructure.
Anticipation
         This ground of opposition was not included in the notice of opposition and was raised at the hearing by Mr. Macaw for the opponent.  Nevertheless, I have considered the citations drawn to my attention and I find that none of them anticipate the invention as claimed.
Patent 458088
         The opponent relied upon the applicants' prior Australian Patent 458088 referred to in the specification.  Patent 458088 is entitled "Porous Products and Process Therefor" and deals with expanded, porous PTFE.
         The specification describes amongst other embodiments a shaped article of expanded PTFE having the following properties:

(a)a matrix tensile strength of 7,300 psi;

(b)a microstructure characterised by nodes interconnected by fibrils (figure 1 is identical to figure 1 of the application in suit);

(c)a fibril length of 5 to 500 microns.

What is not disclosed in the citation is the particular application or use of the article as a vascular prosthesis, and the importance of fibril length for such an application.
         Dr. Emmerson drew my attention to the following well known passage:

"I apprehend the principle is correctly thus expressed: the antecedent statement must be such that a person of ordinary knowledge of the subject would at once perceive, understand and be able practically to apply the discovery without the necessity of making further experiments and gaining further information before the invention can be made useful.  If something remains to be ascertained which is necessary for the useful application of the discovery that affords sufficient room for another valid patent."

See Hill v. Evans (1862) LTNS Vol 6 at 91.

I find it to be inevitable that based upon the disclosures in 458088 it would be necessary for further experimentation to be undertaken before the "invention can be made useful".  Clearly, there is no prior publication here.
"Soyer" Article
         An article entitled "A New Venous Prosthesis" by Soyer et al was published in the December 1972 issue of Surgery (Vol 72, No. 6) and available in Australia on 22 January, 1973.
         This article describes how a prosthetic material made from expanded PTFE was used to replace various major thoracic and abdominal veins in experimental animals.  Various lengths and diameters of expanded PTFE were used.
         Although there is some discussion on pore size, there is no teaching that could be said to disclose the importance of fibril length in achieving tissue ingrowth.  It was contended by the opponent that pore size is related to fibril length.  This is no doubt so, however the view expressed by Dr. Emmerson that pore size and fibril length are not equivalent features is more to the point; thus it is conceivable that the same pore size may be achieved by having long fibrils narrowly spaced as by having short fibrils widely spaced.
         The Soyer article, therefor, does not in my opinion disclose the essential features of fibril length nor the range of allowable fibril lengths.
"Matsumoto" Article
         An article entitled "A new vascular prosthesis for a small caliber artery" by Matsumoto et al was published in the October 1973 issue of Surgery (Vol. 74 No. 4) and was available in Australia on 13 December, 1973.
         This article describes   how in work done in Tokyo vascular grafts of expanded PTFE and ultra lightweight woven TEFLON were investigated.  Grafts of expanded PTFE used in the study were in the form of non‑crimped tubes molded with expanded PTFE and had "the smoothness of the inner surface and high porosity of approximately 85 percent".
         The vascular grafts of expanded PTFE were 3mm internal diameter and 3 to 5cm in length, and were inserted between sections of the dissected femoral arteries in dogs.  The patentcy rate was 100% for from 4.5 to 11 months after the operation, excepting three early thrombotic occlusions due to "technical error".  On the other hand, the grafts of woven TEFLON became occluded by thrombosis from 7 to 101 days after insertion.  In histological studies of the expanded PTFE grafts, microscopic findings showed a well‑formed fibroplasia in the porous layer and a thin well‑attached neointima on the inner surface thereof.  The article describes the expanded PTFE used as being "Gore‑Tex tubes manufactured by W.L. Gore & Associates", and refers to a Figure 1 comprising electron microscope pictures of "expanded porous polytetrafluoroethylene".  Each of the pictures indicates the magnification and includes a scale by which the lengths of the fibrils could be approximately measured.  According to Mr. Macaw, the situation is this:

(i)The method described by the article coincides with that claimed and described in the specification in suit as to purpose, implementation, and results;

(ii)The material used in the method described in the article is certainly the same as that claimed in the specification in suit, since, firstly, it was obtained from the applicants, and secondly, the claimed structure of nodes interconnected by fibrils of greater than 5 microns in length is clearly discernible in Figure 1;

Consequently claims 1 to 3 are fully disclosed by the "Matsumoto" article.
         Certainly, Mr. Macaw is correct on his first point, there can be no doubt about this.  As to his second point, I cannot agree with either of the two allegations which he has made.
         Firstly, I will deal with the matter of the source of the material used by Matsumoto et al in their experiments.  The fact that the expanded PTFE was manufactured by the applicants is no guarantee that the fibril length thereof was within the range specified by the claims under consideration.  However, when the source of the material is considered against the disclosure of the Gore application which states very clearly* that the invention is only achieved within certain limits of fibril length, one might be forgiven for drawing the conclusion that either the material used by Matsumoto et al fell within the class described by the Gore application or that the latter had incorrectly specified the limits for that class.
However any such conclusion appears to me to be irrelevant to the determination of what the "Matsumoto" article disclosed at its date of publication in Australia (i.e. 13 December, 1973) to a person skilled in the relevant art, which is the proper basis for investigating anticipation. (See The General Tire & Rubber Company v. The Firestone Tyre and Rubber Company Limited (1972) RPC 457 at page 485).
*        The specification at page 7 includes the following paragraphs:

"In accordance with the present invention, it was discovered that porous expanded PTFE gave unexpectedly beneficial results when used as an artificial vascular prosthetic when the fiber (fibril) length in such devices was between 5 and 1000 microns.  Within this range and during the healing process, fibroblastic and capillary ingrowth into the prosthetic occur, with uniform neointimal development over the grafts and suture line surfaces.

Below about 5 micron fibril length, tissue ingrowth does not occur and the advantages of this invention are lost.

Above about 1000 micron fibril length, mechanical disadvantages can occur in suturing the vascular graft to the host tube, and blood leakage can become a problem.  This upper limiting range of fibril length is difficult to define quantitatively, however, and depends to some extent upon the skill of the surgeon administering the graft.  Blood leakage can also occur in vascular devices which have long fibrils (exceeding 1000 microns) caused by the driving force of the internal blood pressure.  In the range of 5 to 1000 micron fibril length, however, the prosthetics of this invention both contain the blood and simultaneously allow tissue ingrowth."

Secondly I come to a consideration of the other allegation in Mr. Macaw's second point, i.e. that the nature of the expanded PTFE used is clearly discernible from Figure 1 of the article.  It is true that a first consider‑
ation of that Figure shows a structure which might be nodes joined by fibrils of about 10‑15 microns in length. However, the matter is not so simple. The House of Lords in C. Van Der Lely N.V. v. Bamfords Ltd. (1963) RPC 61 made the following remarks at page 71:

"We were informed that this is the first case in which the question of anticipation has turned on the proper inference to be drawn from photographs, although there have been cases of anticipation by published drawings.  There is no doubt that, where the matter alleged to amount to anticipation consists of a written description, the interpretation of that description is, like the interpretation of any document, a question for the court assisted where necessary by evidence regarding the meaning of technical language.  It was argued that the same applied to a photograph.  I do not think so.  Lawyers are expected to be experts in the use of the English language, but we are not experts in the reading or interpretation of photographs.  The question is what the eye of the man with appropriate engineering skill and experience would see in the photograph, and that appears to me to be a matter for evidence. Where the evidence is contradictory the judge must decide.  But the judge ought not, in my opinion, to attempt to read or construe the photograph himself; he looks at the photograph in determining which of the explanations given by the witnesses appears to be most worthy of acceptance.

The photograph must be looked at through the eyes of the typical addressee of the appellants' specification ‑ the kind of person who would be expected to make a machine of this kind.  Traditionally that is the skilled craftsman with full knowledge of the prior art."

I do not think those remarks are directly applicable to a Tribunal such as this.  Hearing Officers may or may not be lawyers : they are however normally trained in a science or a technology and where this is so, I see no reason why they should not bring their own technical background to bear in appropriate situations.  However, the present situation is a difficult one.  The "Matsumoto" article was published in Australia on 13 December, 1973, and the priority date of the Gore claims is 2 April, 1974.  The investigation of anticipation (see General Tire v. Firestone Tyre supra) in this situation presents some difficulty and I conclude could only be satisfactorily done by reference to expert evidence from persons aware of the state of the relevant art in Australia some 12 years ago.  There is no such evidence on file.
         Consequently, in my opinion, the "Matsumoto" article does not anticipate the Gore Application.
Obtaining
         The evidence on file dealing with obtaining comprises the following documents:

(a)affidavits from the file of US serial number 517415 (i.e. the Goldfarb application);

(b)affidavits from the file of US serial number 457711 (i.e. the Cooper application, and the basic application for the present case);

(c)depositions relating to certain actions in the US ‑

(i)David Goldfarb v. W.L. Gore and Associates, Inc. and Peter Cooper.

(ii)W.L. Gore and Associates v. IMPRA et al.

(iii)David Goldfarb v. IMPRA et al.

Mr. Macaw conceded that the invention so far as claimed in claims 1 and 2 as accepted was not obtained : however he contended that if these claims were to be made fairly based the situation would change.  Thus Mr. Macaw submitted that Mr. Cooper's only perception of the invention was as is presently defined by those two claims : the characterisations added by claims 3 to 6 (as accepted) arose and were obtained from the work of other researchers in the field; of these, one was the opponent, Dr. Goldfarb.  He said that the examples in the specification can be attributed to the work of Dr. Goldfarb (examples 1 and 4), Dr. Volder (example 2) and Dr. Cohn (example 3); in particular, wall thickness, density and porosity are essential characteristics of the vascular graft, and these form part of the invention perceived by Dr. Goldfarb.  Finally, Mr. Macaw submitted that leave to amend ought not be granted in circumstances where the introduction of limiting characteristics of the structure of the prosthetic device would involve introducing features that resulted from the work of either the opponent Dr. Goldfarb or other researchers in the field.
         The evidence on file shows the following:
         Mr. Cooper (the inventor of file) approached the invention from the background of familiarity with the material "Gore‑Tex" manufactured by his employers, W.L. Gore & Associates.  Gore‑tex is expanded PTFE.  He found that when the fibrils were greater than 5 microns in length tissue growth in a prosthesis was enhanced and hence the material appeared suitable for vascular use ‑ this much he had found out in early 1973, and he developed techniques for microscopic examination of the material and had determined that fibril length was an essential factor.  It seems that Gore subsequently provided samples of expanded PTFE to various surgeons for testing purposes.  Dr. Goldfarb, who was a principal researcher at the Arizona Heart Institute was one of these.  The Arizona Heart Institute was not the only institute at which such work was being done.  The litigation referred to in item (c) above arose in the following way. It seems that Mr. Detton (one of the deponents in evidence) was employed by Gore in early 1973 as a liaison officer to work between Gore and the Arizona Heart Institute.  In early 1974 he left Gore and together with some other ex‑
employees of Gore set up a company known as IMPRA.  Dr. Goldfarb applied for a patent for a vascular prosthesis in the US and although still an employee of the Arizona Heart Institute assigned to IMPRA.  This sequence of events plus a subsequent disagreement between Dr. Goldfarb and IMPRA led to the actions listed above.
         None of those actions directly relate to the present issue of obtaining; the associated depositions do, however contain conflicting material. I note also that there are no US Court judgements as a result of those actions before me.
         To prove obtaining, it is necessary for certain requirements to be satisfied.  Thus it must be established:

1.What the invention is that has allegedly been obtained;

2.Whose invention it was when the alleged obtaining occurred;

3.That the claim defines, or includes within its ambit, the invention allegedly obtained;

4.That the applicant actually obtained the invention from the opponent, or from a person of whom the opponent is the legal representative, assignee, agent or attorney, prior to the priority date of the claim.

(See Space‑Cell Systems (Aust.) Pty. Ltd. v. E.P.M. Concrete Pty. Ltd. (1979) 49 AOJP 2018).
         I shall now deal with these requirements in the context of the facts of this case.
         It is convenient to consider items 1 and 3 together : Mr. Macaw alleges that the features which have been obtained are as follows:

(i)the upper fibril length limit of 1000 microns;

(ii)the preferred fibril length range of 20‑100 microns; and

(iii)the essential characteristics of wall thickness, density and porosity of a vascular prosthesis.

(As far as the characterisation of claim 4 is concerned, i.e. that the expanded PTFE has a matrix tensile strength in at least one direction exceeding 7,300 psi, this was published in Australia on 23 November, 1972 in the specification of Gore's own Australian Patent No. 458088).
         Requirement (1) is evident in items (i), (ii) and (iii).  Coming to requirement (3), whereas claims 1 and 2 presently do not include the limitation of upper length of fibrils, pursuant to my remarks under the heading of Section 40, they will need to do so to be fairly based.  At that stage all claims will include item (i) and two claims will include item (ii), as limitations thereof. No claim will feature item (iii).  Consequently requirement (3) is satisfied in respect of items (i) and (ii) only.  I shall ignore item (iii) in my subsequent remarks.
         As to requirement (2), Mr. Macaw has pointed out that item (i) comes from the work of Dr. Cohn, and the lower limit in item (ii) comes from the work of Dr. Goldbarb.  The source of the 100 micron preferred upper length for the fibrils is not clear, however Mr. Macaw did suggest at the hearing that Dr. Eiseman or Dr. Sharpe could be that source.
         I come now to consider the final and most telling requirement, i.e. that the applicant actually obtained the invention from the opponent.  Of the three items listed alleged to have been obtained, it seems to me that only part of item (ii), i.e. the lower limit of the preferred range for fibril length (20 microns), remains to be considered, as this is the only feature presently claimed (or in my view even requiring to be claimed ‑ see my remarks re section 40) which Mr. Macaw has attributed to the work of the opponent, Dr. Goldfarb. Were I wrong on this view, I do not think my following remarks would lead to any different conclusion, as it seems to me that those remarks would be equally applicable to the question of obtaining of at least items (i) and (ii) (in whole).  The applicant is the maker and supplier of the expanded PTFE.  Mr. Cooper is their employee and he is the expert in expanded PTFE.  As Mr. Macaw has conceded, Mr. Cooper perceived the invention defined by claims 1 and 2 as accepted.  It seems to me that in successfully planting vascular prostheses, surgical skill would be required; it follows that it would be reasonable that Gore should seek the assistance of surgically trained personnel to use their sample materials and report the results.  On the evidence before me that was the situation, and it was Mr. Cooper who formed ideas from examination of the microstructures and of the various reports and the correlation thereof.
         I take the view that surgical success is to be distinguished from the success of the invention per se, and in this respect the researching Doctors come into the category of assistants to Mr. Cooper, who I see as the real inventor.  I conclude therefore that requirement (4) has not been satisfied.
Prior Claiming
         The opponent alleges that the claims in suit are prior claimed by the opponent's Australian patent application 76868/74 which has a priority date of 24 October, 1974.
         As the priority date of the Gore specification is 2 April, 1974 there is, prima facie, no valid objection of prior claiming.
         The argument developed by Mr. Macaw is that the applicant is not entitled to convention priority and thus the priority date of the claims in suit is the date of lodgement in Australia (i.e. 27 February, 1975).
         Mr. Macaw's argument was based on the fact that Mr. Cooper was the applicant in respect of the basic application in the US and consequently (as only the inventor may apply in the US) he is said to be the inventor in respect of the application in suit, and assignor to Gore.  However, pursuant to the requirements of sections 34 and 141, the Gore application is not entitled to convention priority as (in the view of the opponent) Mr. Cooper is not the true inventor.
         I have already found that the evidence is not of the cogent and compelling nature required to satisfy me that obtaining has occurred.
         However, I am of the view that there is an even more compelling reason for not agreeing with Mr. Macaw's submission.
         The remedy where obtaining is found is set out in the provisions of sub‑section 60(3) which reads as follows:

"60(3)Where the Commissioner finds that the invention, so far as claimed in any claim of the complete specification, was obtained from the opponent, he may, on application made in accordance with the provisions of the Act, grant to the applicant a patent for the invention, so far as so claimed, and the claims of the complete specification of that patent shall have the same priority date as the priority date of the first‑mentioned claim."

It seems to me that pursuant to these provisions, even had I found obtaining to exist, Mr. Macaws' submissions on this matter would be irrelevant.
         Consequently I reject the allegation of prior claiming.
Summary
         In summary then, I dismiss the grounds of opposition excepting those relating to section 40: the defects existing under this section are serious, and I award costs against the applicant.
         I allow the applicant 60 days from the date of this decision to apply to amend the specification to my satisfaction.

(J.L. ROVETA)