Goldfarb v. Wl Gore & Associates Inc., 2001 FCT 45

Date: 20010209

Docket: T-2567-87

       Citation: 2001 FCT 45

BETWEEN:

           DAVID GOLDFARB

       Plaintiff/

   Defendant by Counterclaim

          - and -

W.L. GORE & ASSOCIATES, INC.

Defendant/

   Plaintiff by Counterclaim

   REASONS FOR JUDGMENT

LEMIEUX J.:

INTRODUCTION AND BACKGROUND

[1]         The sole question to be decided in this subsection 43(8) Patent Act proceeding (the "Act"), now repealed, is who, as between Dr. David Goldfarb and Peter Cooper, having assigned his invention rights to his employer, W.L. Gore & Associates Inc. ("Gore"), is the first inventor of the appropriate internal structure for an artificial vascular prosthesis for implantation in the human body to replace natural veins and arteries. The material used in the fabrication of this prosthesis is expanded porous polytetrafluoroethylene ("ePTFE") with the internal microstructure consisting of nodes interconnected by fibrils. This microstructure, and in particular, the distance between the nodes (in other words, the fibril length) is said to be the invention because it permits and controls tissue cellular ingrowth and assures the establishment and health of a thin viable neointima, consisting of endothelial cells, necessary for smooth blood flow.

(a) Dr. Goldfarb's patent application in Canada

[2]         Dr. Goldfarb filed his patent application in Canada on January 16, 1975. Gore followed by filing in Canada on March 19, 1975, both claiming priority dates from U.S. filings.

[3]         Dr. Goldfarb, in his application, wrote that a principal aspect of his invention was to provide a vascular prosthesis capable of replacing or bypassing veins and arteries having relatively small diameters as well as those vessels of intermediate and larger pore. He identified the prior art grafts which were machine-woven from tightly twisted dacron or teflon fibres.

[4]         Dr. Goldfarb identified the problems surgeons encountered with such grafts and spelled out the benefits of the structure derived from ePTFE, that is, a homogeneously porous vascular prosthesis with small nodes interconnected with extremely fine fibril and characterized (a) by an average internodal distance (i) large enough to allow the migration of typical red cells and fibroblasts and (ii) small enough to inhibit both excessive blood flows at normal pressure and excessive tissue ingrowth; and (b) an average of wall thickness which is (i) small enough to provide proper mechanical conformity to adjacent cardiovascular structures (suturing) and (ii) large enough to prevent blood clotting and excessive tissue ingrowth.

[5]         Dr. Goldfarb noted the methods and techniques to expand PTFE have been known for many years and ePTFE has been used, without clinically meaningful or reproducible success, for artificial vessel replacement quoting Soyer et al. in Surgery, "A New Venus Prosthetic", vol. 72, page 864, December 19, 1972, and Matsumoto et al. in Surgery, "A New Vascular Prosthesis for Small Caliber Artery", vol. 74, October 19, 1973.

(b)             Mr. Cooper's Canadian filing

[6]         Mr. Cooper, in his March 19, 1975 patent filing, abstracted his application in the following terms:

This invention provides an artificial vascular prosthesis suitable for implantation to replace damaged, defective or occluded veins or arteries. The prosthesis comprises of a tube of expanded porous, polytetrafluoroethylene possessing a microstructure consisting of nodes interconnected by fibrils. The suitable range of fibril length for such a prosthesis is 5-1000 microns, with the preferred range being 20-100 microns.

[7]         Mr. Cooper described the prior art in terms similar to what Dr. Goldfarb had said in his patent application. He also described experimentation on grafts constructed of synthetic textile materials and said none had been entirely successful. He said for total success, an artificial arterial prosthesis must provide an open pathway for blood to pass along its entire length and additionally must not generate embolization to the distal arterial bed.

[8]         Mr. Cooper, referred to certain experiments implanting a vascular prosthesis made with ePTFE in animals. He provided four examples, showing the preferred range of fibril length at about 20-100 microns.

[9]         In his first example, Mr. Cooper said two series of experiments were conducted using dogs for the animal model and using the two carotid arteries and two femoral arteries for the segmental replacement site. In both experimental series all grafts were expanded porous ePTFE tubes with variations in length (4 cm) in diameter (4 mm) as well as the wall thickness (20-32 mils), the density of the material (0.25-0.34 g/cc) and the fibril length (5-1000 microns).

[10]       The first series involved 64 implantations of which 36 grafts had been harvested, the remaining being in living animals with palpable pulses over the grafts. He said this experiment yielded an expected patency rate of 87.5% for the entire series. He said histological examination of the patent grafts demonstrated fibroblastic ingrowth, capillary formation and the development of uniform, smooth neointima throughout the lengths of the graft as well as over the suture line.

[11]       Mr. Cooper described the second series of experiments involving the implementation of 107 grafts of which 51 had been harvested. Out of those harvested, a patency rate of 76.4% resulted. In these two series all grafts with a fibril length ranging from 5 to 20 microns yielded a 100% patency rate.

[12]       In his second example, Mr. Cooper describes that 32 grafts constructed from ePTFE were substituted in one carotid artery in each of 32 sheep. Of the grafts harvested, he indicated they were all patent. The fibril lengths were 3 to 150 microns.

[13]       In his third example, he wrote that grafts of ePTFE were interposed in the carotid and femoral arteries and femoral vein of mongrel dogs and that 36 grafts had been implanted of which 18 had been harvested, all of them patent. The fibril length ranged from 25 to 1000 microns.

[14]       In his fourth example, he described experiments involving 12 grafts interposed in the abdominal aortas of twelve dogs of which five had been harvested and all of them patent. The fibril lengths were 20 to 40 microns.

(c)             The conflict proceeding and the Commissioner's decision

[15]       After receiving these two applications, the Commissioner of Patents (the "Commissioner") declared conflicting claims and defined the subject matter in conflict by drafting eight claims. The Commissioner then received, under then, but now repealed, subsection 43(5) of the Act, sealed affidavit evidence and on June 11, 1987, awarded four conflict claims to Dr. Goldfarb and four conflict claims to Gore.

[16]       The Commissioner awarded conflict claims C-1 to C-4 to Gore on the basis that the date of invention was on May 19, 1973, when Mr. Cooper exhibited, during an Open House at Gore's Flagstaff plant in Arizona, photomicrografts of slides evidencing tissue ingrowth in artificial veins implanted in dogs, as contrasted to an invention date of January 16, 1975, the date when Dr. Goldfarb filed his Canadian application.

[17]       The Commissioner awarded claims C-5 to C-8 to Dr. Goldfard based on an invention date of mid-July 1973 as the result of his experiment known as the 64-graft series as contrasted to a date of February 1974 for Mr. Cooper. February 1974 is when Mr. Cooper received a report by Mr. Detton, Research Coordinator at Gore in Flagstaff Arizona. This was a progress report on the research being conducted by various medical researchers on ePTFE grafts over the previous six months.

THE FACTS

(a)             Prior experimentation on ePTFE before the Goldfarb/Gore linkage

[18]       Before he joined the Arizona Heart Institute ("AHI") in January of 1973, Dr. Goldfarb, during the 1960s, had conducted research on artificial vascular grafts for human applications at John Hopkins University and at the University of Pittsburgh. These grafts were made of woven or synthetic materials and typically were for the replacement of large veins since they had a minimum internal diameter of 8 to 10 mm; attempts at implanting smaller artificial grafts had been unsuccessful.

[19]       Mr. Cooper joined Gore in the early 1960s starting as a machine operator and then becoming a shift supervisor. In 1964-1965 he opened a sales office in California for Gore and after his return, he designed at Gore PTFE coated products for the wire and cable industry. In 1967, he was transferred to Flagstaff, Arizona, as plant manager to a new plant established for the production of PTFE coated wire and cable products.

[20]       In May of 1970, Robert Gore filed a patent application for ePTFE including the methods for making ePTFE tubing. Gore and Mr. Cooper wanted to develop uses for ePTFE tubing. One of those uses was for medical applications. In the Fall of 1970, Gore equipped its Flagstaff plant with a tubing extruder to make ePTFE tubing.

[21]       Mr. Cooper's first medical research contact was in December 1970 with Dr. Ben Eiseman, a surgeon at the University of Colorado in Denver, who implanted an ePTFE Gore tube in a dog's vena cava in January 1971. Dr. Eiseman and doctors associated with him (Drs. Norton, Soyer and Kelly) began conducting experiments during the summer and late fall 1971, implanting ePTFE vein grafts in experimental animals (dogs and pigs). By November 11, 1971, Dr. Eiseman's group had done 31 animal experiments using ePTFE tubes supplied by Gore. None of those tubes clotted and there were patencies of three months which Dr. Eiseman reported as being "very exciting".

[22]       In December 1971, Dr. Eiseman's group performed an implant of a Gore-made ePTFE graft, 9mm in diameter, in the portal vein of a human. This was said to be the first implant of any prosthetic portal vein of any material in a human. The operation was successful and the patient was discharged.

[23]       As a result of these developments, Dr. Eiseman and his team prepared a paper for presentation, on June 22-23, 1972, at the Society of Vascular Surgery. Mr. Cooper reviewed a draft summary (an abstract) of this paper and made corrections in the description of the characteristic of the Gore tubes. Mr. Cooper is named as one of the authors of the paper.

[24]             Throughout the latter part of 1972, Gore, through Mr. Cooper and Mr. Richard Mendenhall, another Gore employee, expanded their medical research contacts and forwarded to them sample grafts of ePTFE tubing for research purposes using a new numbering system to keep track of the tubing by lot number. Among the medical researchers contacted by Gore were Dr. Lawrence H. Cohn of Peter Bent Brigham Hospital in Boston and a team of doctors at the University of Utah, Drs. Jarvik, Knolff and Volder.

[25]       On August 15 and 21, 1972, Mr. Cooper summarized the work being done at various medical centers on Gore ePTFE made grafts (hereinafter known as "GORE-TEX grafts") in two reports to its president Bill Gore. In his August 21, 1972 report, Mr. Cooper indicated that he now thought tissue ingrowth was a good thing.

[26]       On September 11, 1972, Mr. Cooper contacted Dr. Sharp in Akron, Ohio, and described to him the structure of ePTFE as a matrix of nodules interconnected by fibrils with open pore spaces between the fibrils. On that same date, he wrote to other medical researchers giving them similar information.

[27]       As noted, throughout the fall of 1972, medical research continued on the GORE-TEX grafts. As well, refinements were made to the production process at Gore for the making of such grafts or tubes and as well how best to identify its internal structure because tubes that are identical in density and dimension can have different internal structures. Measurement at Gore of internal structure of its manufactured grafts is now made by way of an ethanol or alcohol bubble point measurement ("EBP").

[28]       On October 31, 1972, Mr. Cooper sets up an experiment with three different manufacturing processes to identify variations in the Gore grafts' internal structure. These manufacturing processes are by: (1) slow hand expansion, (2) very fast gun expansion and, (3) a modified standard expansion. On November 2, 1972, Gore, with the participation of one of its employees Harold Green who joined Gore in the fall of 1971 as an engineer responsible for manufacturing ePTFE tubing, launched an experiment known as the "Three-Structure Experiment". The tubes made by the slow hand expansion were called within Gore as "poker chipped" tubes. These grafts have low EBP (large pores) whereas the gun-produced grafts have high EBP (small pores) and were manufactured at Gore between November 2^nd and 8^th, 1972 before Dr. Goldfarb began his experiment on GORE-TEX tubing.

[29]       On November 10, 1972 , Mr. Cooper sent grafts made of GORE-TEX tubing of the three variants in the Three-Structures Experiment to Drs. Eiseman, Volder, Sharp and Kerth and stated that Gore had established a relationship with an electron microscope company to look at the internal structures of the tubes.

[30]       In December 1972 and, as noted by Dr. Goldfarb in his Canadian patent application, Dr. Soyer's article was published in Surgery and Mr. Cooper was named as one of its authors. The ability of a GORE-TEX made vascular graft was disclosed. What was not know was why it would remain patent.

[31]       In January of 1973, both Drs. Volder and Cohn reported successful implants in various types of animals in the context of the Three-Structures Experiment.

(b)             The link between Dr. Goldfarb and Gore

(1)             February 1973

[32]       After determining Dr. Goldfarb would consider using ePTFE Gore tubing in his research, Richard Mendenhall from Gore on February 2, 1973, sent Dr. Goldfarb samples of ePTFE tubing which Gore had previously fabricated for the "Three Structure Experiment" and several reprints regarding the use of GORE-TEX as a vascular prosthesis and as an oxygenator. Mr. Mendenhall wrote to Dr. Goldfard "we feel that this material might prove useful as a synthetic coronary artery bypass graft".

[33]       After receiving this material from Gore, Dr. Goldfarb testified he cut thin slices of the sample tubing and examined it under a 100 power optical microscope. Dr. Goldfarb said he knew from the prior teachings of Dr. Wesolowsky as well as from his own past experience that a successful graft requires tissue ingrowth in order for the blood to be exposed to the natural tissue which forms in and around the graft. He also said he knew, to achieve tissue ingrowth, the graft must have open pore spaces into which fibroblast (average 5 microns) can enter and, in addition, the thickness of the wall of the graft must permit cellular infiltration and be flexible and suturable.

[34]       Dr. Goldfarb testified, after microscopically examining the Gore sample tubing, he saw, at that time, the ePTFE material consisted of nodes and fibrils with the nodes defining the open pore spaces which would permit desired tissue ingrowth. He testified he felt the ePTFE tubing would function successfully as a vascular prosthesis if the pores in the material could be altered so as to best accommodate the fibroblast for the purpose of healing the graft into the patient's tissue.

[35]       He said, in his testimony, it became clear to him after examining ePTFE sample, the important parameter in terms of allowing cells to enter was the distance between the solid ePTFE nodes and he realized that the open distance between the nodes, "pore size" or "internodal distance", would have to be at least 5 microns, the approximate diameter of the disk-shape fibroblast in order that it may fit between the nodes. Based on his work with other graft materials, Dr. Goldfarb testified he knew the desired tissue ingrowth occurred between the solid portions of synthetic graft material, known as interstices and the tissue would ingrow between the solid ePTFE nodes.

[36]       Dr. Goldfarb testified the fibrils which connected the nodes of ePTFE grafts appeared to him to be quite thin and flexible and capable of moving to allow cells to pass through by being pushed apart. He testified from his experience, a fibroblast is a highly mobile and motive cell capable of changing its shape to fit through a given pathway.

[37]       Again, drawing from the teachings of Dr. Wesolowsky, Dr. Goldfarb testified he realized, after examining the Gore ePTFE sample before implant, the distance between the nodes should not be so large as to allow bleeding through the wall of the graft. He said he knew the distance between the solid ePTFE nodes should be smaller than the upper limit capable of preventing bleeding through the wall of the device. He testified the exact numerical value of the upper limit was not known, but could easily be determined by routine experimentation.

[38]       On February 8, 1973, Mr. Cooper and Mr. Mendenhall visited Dr. Goldfarb at the AHI in Phoenix, Arizona. Dr. Goldfarb testified this was a substantial meeting where he explained to Gore's people the need for tissue ingrowth in order to make a graft successful and the key to graft success was its microstructure with a pore size (fibril lengths or internodal distances) of at least 5 microns so as to allow a fibroblast to pass through but not so large as to allow bleeding through the wall of the graft. On the other hand, Mr. Cooper testified this meeting was an introductory one and there was no discussion on the structure of the grafts or "pore size", or fibril lengths or internodal distance. Mr. Mendenhall did not testify in these Canadian proceedings as he had in the United States.

[39]       On February 14, 1973, Mr. Cooper sent Dr. Goldfarb "a variety of sizes of GORE-TEX tubes for your animal artery prosthetic experiments". Dr. Goldfarb said he had this tubing cut into grafts for implantation after observing it under a microscope and mentally noting the internodal distance. However, he made no written recordings of this fact.

(2)             Dr. Goldfarb's first series of experiments with Gore ePTFE

[40]       On April 19, 1973, Mr. Cooper sent a letter to Dr. Goldfarb enclosing ePTFE tubing for experimentation which reads as follows:

The enclosed GORE-TEX tubes represent the latest attempt to achieve satisfactory patency rate in small artery prosthetics. We have penetrated the walls of the tubes with many (160-in) 50-100 micron holes to allow direct tissue growth through the tube walls. Hopefully these pathways will allow rapid, firm attachment of the neointema surface.

Up to date the research reports are enclosed. We will continue to provide new materials and experimental results as they become available. [emphasis mine]

[41]       The up-to-date research reports included an abstract from a paper presented by Dr. Volder at the April 7-9, 1973 ASAIO meeting and a report by Dr. Sharp to Mr. Cooper dated April 2, 1973, which Dr. Goldfarb testified were not enclosed and later could not remember if they were enclosed in Mr. Cooper's April 19, 1973 letter.

[42]       On April 25, 1973, Dr. Goldfarb began a first series of experiments using 21 ePTFE grafts implanted in seven dogs. Dr. Goldfarb testified before implanting the ePTFE tubing, he viewed the structure of the material under a microscope to insure that the internodal distances fell roughly within his desired range. Unfortunately, Dr. Goldfarb did not transcribe his pre-implant internal distance observations in his laboratory records.

[43]       The implanted grafts were removed from the animals after 21 days and histological slides were prepared from grafts specimens and preserved in paraffin blocks. Autopsy forms were maintained by James Moore who had been Dr. Goldfarb's laboratory technician when he was at the University of Pittsburgh. Again, Dr. Goldfarb did not record in writing the post implant fibril length observations which he said he made visually.

[44]       On May 23, 1973, Dr. Goldfarb harvested the right carotid graft implanted in dog 2-73. It was patent. Other grafts harvested from dog 2-73 also proved to be patent showing the requisite tissue ingrowth. Dr. Goldfarb testified the internodal distances for dog 2-73 and others were above 5 microns because, if it was otherwise, he would not have implanted them. Dr. Goldfarb said these grafts likely had between 20 and 30 microns in internodal distance. These post-harvest measurements, he said, confirmed his pre-implant measurements, but unfortunately, as noted, he did not record neither of them.

[45]       Dr. Goldfarb testified that in May of 1973, Mr. Mendenhall visited him a second time. He testified he told Mr. Mendenhall what he felt were the appropriate specifications for a successful small artery artificial vascular graft. He said he told him the internodal distance of the material had to be between 5 and about 100 microns with a preferred internodal distance of 20 to 30 microns, and a wall thickness of .25-.75 mm as well as be compliant and flexible.

[46]       Dr. Goldfarb testified in the spring of 1973, more likely in June of that year, he met with Mr. Dan Detton. Dr. Goldfarb testified he transcribed his specifications for successful grafts on a piece of paper which he gave to Mr. Detton in the restaurant where they met. Dr. Goldfarb testified shortly after giving that piece of paper to Mr. Detton, he received a call from Harold Green at Gore. Dr. Goldfarb testified during this telephone call he reiterated his specifications. Harold Green testified in these proceedings and confirmed Dr. Goldfarb's testimony as to Dr. Goldfarb's specifications in terms of internodal distance, wall thickness, length and internal diameter. Mr. Green said these specifications became known at Gore as the "Goldfard structure".

(3)             What was happening at Gore in February-May 1973

[47]       A few days after Dr. Goldfarb's meeting with Messrs. Cooper and Mendenhall, Mr. Cooper received, on February 12, 1973, a report from Dr. Sharp providing him with the test results of the "GORE-TEX graft". Dr. Sharp wrote:

As of this date, I can only give you a partial analysis. We used the 21-day patency period has being the maximum evaluation time. All the grafts have been inserted but some have not gone the full 21 days yet. The results so far are as follows: 1) 416-10312-4 grafts inserted, 2 patent at 21 days; (2) 423-11082-2: 2 patent at 16 days; (3) 423-11082 (.29): 2 patent at 16 days, 1 patent at 20 days , 1 clotted at 24 hours, and 2 are still patent at 4 days; (4) 423-11082 (.30): 2 are patent at 5 days; (5) 416-10312-2: all clotted in less than 10 days time.

Microscopic studies and gross studies of inside of the patent artery at 21 days demonstrate a rather thick inner fibroses capsule or neointima which is very poorly attached to the prosthetic material ... It is too early to form definite conclusion from this study, but I think it if fair to say that all of the samples that which have received did not demonstrate a high degree of performance in the small artery position. [emphasis mine]

[48]       Mr. Cooper testified the grafts with lot number 416-3 were the "poker chipped" grafts with the lowest EBP measured in pound per square inch which corresponded to the largest pore size in the Three-Structure Experiment.

[49]       On March 21, 1973, Dr. Kelly wrote to Mr. Cooper advising him he had an opportunity to review all of the microscopic slides on GORE-TEX vein grafts done during the past four months. He said although all of them were clotted, "there is one outstanding feature which is worthy of comment". He said all of the medium density GORE-TEX grafts (.48 grams per cc) were only sparsely permeated by adjacent cells from the intimal adventitial surface. He said all of the low density grafts (.27 grams per cc) were totally infiltrated by adjacent cells. He added "obviously the critical aperture lies somewhere between these two densities". He wrote it would be of great interest to the research team in Denver "to know what the actual microscopic pore size is in these two separations". He asked Mr. Copper to have one of his microscopist measure the minimum, maximum and mean pore size.

[50]       On April 2, 1973, Dr. Sharp provided Mr. Cooper with a report on the final testing of four samples of GORE-TEX material. He attached microphotos. In particular, he reported on the group I (GORE lot 416-3 (.31g/cc) (the poker chip structure). He said there were a total of four grafts inserted in the dog's carotid artery and that two remained patent for 21 days and two clotted before 21 days in another animal. He said the low power microscopic views demonstrated excellent fibroblastic infiltration of the wall of the graft and a fairly thick, but well attached neointima. He discussed the results of the other groups. He observed that only in Group I was there neointimal attachment as well as fibroblastic ingrowth of tissues on capillaries through the interstices of the wall graft. He concluded Group I proved to be the most promising. He recommended that further studies be carried out with Groups I, II and III with a recommendation that the wall thickness should be thinner and at least 12 grafts of each group should be tested and porosity measured.

[51]       On April 9-11, 1973, Dr. Volder presented a paper at the conference of the American Society of Artificial Internal Organs. He reported that high porosity GORE-TEX grafts implanted in the carotid arteries of sheep remained patent for up to six months with smooth neointimas.

[52]       On April 17, 1973, Dr. Kelly forwarded to Mr. Cooper four histological slides from four grafts harvested from dogs after one month. Mr. Cooper testified that Dr. Kelly had mis-labelled the manufacturing lot numbers from which the histological slides came from. Mr. Cooper said he determined from the internal diameter, from the outside diameter and from the density measurements that one of the lots Dr. Kelly labelled "416-11172-10(?)" was really lot 423-11072-3 sent to Dr. Eiseman on November 21, 1972, along with lot 416-11172-10 in the context of the "Three Structure Experiment".

[53]       On Easter Sunday, April 22, 1973, Mr. Cooper testified, during a private children's party and Easter egg hunt, he viewed Dr. Kelly's slides and discussed them with Dr. Davee, a Flagstaff internist, and with John Giovale, a Gore engineer. He testified he realized that cellular ingrowth can occur between the nodes and the fibrils are not a bar to cellular ingrowth.

[54]       The next day, that is April 23, 1973, Mr. Cooper testified he took photographs of Dr. Kelly's slides and put a scale on the photograph of the slide from dog 1571's left femoral vein so that fibril length (internodal distance) could be measured from the scale. He testified he instructed Harold Green that additional photographs were to be taken. Copies of these photographs were distributed to researchers in late May 1973.

[55]       On May 1 and May 2, 1973, Mr. Cooper recorded in his lab book (P-Ex 79) the results of his analysis of the photographs he made from the slides sent by Dr. Kelly. On May 1, 1973 he wrote:

I want to maximise the amount and rate of tissue ingrowth into GORE-TEX vascular prosthetics. Two qualities are necessary. (1) uniform "poker chip" structure and (2) a "minimum skin at both the OD and ID surfaces.

Tissue has invaded GORE-TEX where the nodes are approximately 10-30 microns thick with most separation between nodes about 50-100 microns (photo 1). Other structures having approximately 5-10 microns node dimensions and spaces from about 5-30 microns do not appear to allow ingrowth (photo 2). [emphasis mine]

Mr. Cooper noted that both photos were from slides of grafts from femoral veins in dogs in which grafts failed in terms of patency.

[56]       On May 2, 1973, Mr. Cooper entered further information in his lab book about the manufacturing conditions and pictures of the ID and OD surfaces of the graft in dog 1571, as well as a comparison photograph from another of Dr. Kelly's slide of a graft using a gun-expanded (small pore size) lot.

[57]       Mr. Cooper testified making a thin walled poker chipped tube (0.32-inch wall) with a different extruder on May 3 and 4, 1973. During the summer of 1973, the extruding equipment was upgraded so as to produce a tube with less skin.

[58]       Dr. Cooper testified that on May 8, 1973, he and Mr. Giovale visited a pathologist in Flagstaff to review Dr. Kelly's slides or photographs made from them.

[59]       On May 9-11, 1973, Mr. Detton started his work at Gore as liaison with researchers working with GORE-TEX ePTFE grafts. He visited Dr. Volder and others at the University of Utah and wrote in his trip report that Dr. Volder was experimenting to determine the most appropriate GORE-TEX structure (i.e. pore size, density, wall size, etc.) (D-tab 202).

[60]       Mr. Cooper testified on May 17, 1973 he attempted to make a thin-walled tube from film with 50-micron internodal distance, by wrapping the film in layers around a mandrel, hoping to get a tube which would allow tissue ingrowth. It did not work.

[61]       On May 19, 1973, Gore had an Open House at its Flagstaff plant to celebrate the completion of its plant expansion. Exhibits were posted for viewing by visitors. Mr. Cooper testified he had the idea of exhibiting "before and after" photographs using a photograph made from a slide by Dr. Kelly and showing tissue infiltration as the "after" photograph and a slide of a Gore prosthesis before implant as the "before" photograph. The "before" photograph had a scale used to read off fibril length (internodal distance). It is not from the actual lot sent to Dr. Kelly.

[62]       On May 30, 1973, Mr. Detton visited Dr. Goldfarb in Phoenix and in his trip report says he provided Dr. Goldfarb with the findings from Drs. Sharp and Volder regarding tissue ingrowth in the largest pore size grafts. Mr. Detton records that Dr. Goldfard advised him that he had recently inserted approximately 16 to 20 GORE-TEX grafts in dogs and that one of the grafts implanted was patent at three and a half weeks. The other three were not harvested, i.e. were still in the dog and believed to be free of trombosis at four weeks. Mr. Detton wrote Dr. Goldfarb told him GORE-TEX would become a successful prosthesis once the proper surgical technique was developed and once suitable GORE-TEX structures had been identified.

[63]       On June 1, 1973, Messrs. Cooper and Detton visited Dr. Kelly in Denver; Mr. Detton wrote a trip report of that meeting. It indicates he was showed photographs of tissue ingrowth into the poker chipped GORE-TEX grafts.

[64]       On June 6, 1973, Mr. Detton visited Dr. Goldfard and Mr. Moore. He made a trip report. The initial meeting with Mr. Moore, as Mr. Detton wrote it, consisted of an explanation of the findings of recent research relating to fibroblastic cellular and capillary ingrowth in GORE-TEX made grafts. Another aspect of his conversation with Mr. Moore related to a discussion of GORE-TEX structural variations and their potential significance in developing a successful vascular prosthesis. His trip report records he showed Mr. Moore photographs of the slides made by Dr. Kelly. Later that day, Mr. Detton met with Dr. Goldfarb but his trip report does not reveal the details of the conversation he had with him.

[65]       On June 8, 1973, the day after Dr. Goldfarb had successfully harvested his second graft, Mr. Cooper made a notebook entry about ways of overcoming manufacturing difficulties in making poker chipped grafts with thin walls and without skin. The focus of his observations are to improve tissue ingrowth and cellular migration.

[66]       On June 13, 1973, the day of Dr. Goldfarb's third successful graft, Mr. Detton visited him, Mr. Moore and Dr. Dietrich at the AHI. He wrote up a trip report Mr. Detton said he explained to them, during surgery on a dog, the tissue and capillary ingrowth findings and Gore's current efforts to define structural differences and their relationship to ingrowth, neointima viability and patency. Mr. Detton was present that day when Dr. Goldfard harvested graft 459-04133-9 which had been selected by Mr. Cooper and sent to Dr. Goldfard on April 19, 1973. It was a fully perforated tube, with 160 needle-punctured perforations per square inch. A second dog was examined and all four grafts showed signs of clotting. They were made from Lots 448-12222-1 and 2.

[67]       The record indicates that in late June 1973, Mr. Detton visited various researchers to explore the possibilities of GORE-TEX as an artificial vascular graft.

(4)             Dr. Goldfarb's second series of implants using Gore ePTFE

[68]       At the beginning of July 1973, Dr. Goldfarb was joined by Dr. Charles Campbell. Dr. Goldfarb testified that on July 11, 1973, he began his second series of implants at Arizona State University and that the purpose of conducting this series was to confirm his specifications and to narrow down the ideal structure.

[69]       The first implant was on dog 10-73 and following that, Dr. Campbell, under Dr. Goldfarb's supervision, implanted the grafts in the animals in this series. Dr. Goldfarb testified, as he had done in the first series, he and/or Dr. Campbell would review the grafts in this second series microscopically before the implant and after harvest to insure that the GORE-TEX material possessed Dr. Goldfarb's specifications and he said they did. As with the first series, the harvested grafts in the second series were placed in paraffin.

[70]       Mr. Detton recorded, in a trip report, a meeting with Drs. Goldfarb and Campbell on July 18, 1973, and he said one of the purposes of that meeting was to determine those GORE-TEX structures which had provided the most favourable results and to eliminate those which had proved to be unacceptable. His report records the discarding of certain grafts made in certain lots of ePTFE material, the small pore size grafts. Dr. Goldfarb, in his testimony, did not recall that meeting but said Mr. Detton would not have assisted in determining the favourable structure.

[71]       On August 2, 1973, the first patent grafts in the second series were harvested by Drs. Goldfarb and Campbell. On August 6, 1973, the second set of patencies in the second series were harvested and the next day, on August 7, 1973, the third set of patencies in that series was similarly harvested and note of the internodal distances was made.

[72]       In a trip report dated September 18, 1973, after visiting the Arizona Heart Institute, Mr. Detton recorded the results of a comprehensive review of the success and failure rates relative to various GORE-TEX structures in the second series directed by Dr. Goldfarb which he said "produced some rather interesting but inconclusive results" and was not surprised "as the initial series of grafts was designed to merely indicate structural likelihood for favourable grafts". He reported as follows:

The second series of grafts implemented during July included 10 grafts of which 7 remained patent beyond the 21-day test. These grafts ranged from 4.9 mm in internal diameter to 3.0 mm in internal diameter and produced a patency rate of 70%. The pore size would be approximated at 10 to 20 microns which would certainly allow for both fibroblastic tissue invasion as well as capillary invasion into the interstices of these grafts. These patency rates, considering the extreme difficulty of the dog as a test site are far from discouraging and will be followed with a second series of implants.

(5)             Events before Dr. Goldfarb's 64-graft series

[73]       On August 10, 1973, Alan Uebler, Gore's patent agent, contacted Mr. Cooper after Robert Gore had discussed with him the possibility of obtaining an additional patent on the use of poker chipped GORE-TEX tube as an artificial artery or vein. He wrote to Mr. Cooper this possibility existed "if we can establish its new, useful, and non-obvious characteristics over existing products". He asked him to gather his records.

[74]       Mr. Cooper followed up on August 21, 1973, with a memo to Mr. Uebler to whom he sent a second memo that same day which reads:

First, we have large holes from ID to OD between the dense nodes. The nodes spacing is in the order of 50-100 microns using optical measuring techniques.

Second, the holes are bridged from OD to ID with a multitude of fibrils.

Now, here is the point. The fibrils contain the blood even at arterial pressures due to hydrophobic and probably filtering properties but are not an obstacle to tissue invasion! On the contrary, the fibrils may encourage rapid tissue ingrowth! [emphasis mine]

[75]       On August 10, 1973, Mr. Detton recorded a trip visit to Drs. Kelly and Eiseman. Dr. Kelly reported he had completed graft placement with large pore (65 microns) size GORE-TEX in eight dogs and was enthusiastic about the potential for GORE-TEX as a small caliber arterial prosthesis.

[76]       On August 23-24, 1973, Mr. Detton visited Dr. Volder in Salt Lake City. Dr. Volder produced the three latest GORE-TEX vascular prosthetic grafts harvested from sheep for Mr. Detton's observation. These grafts had been harvested the previous week. Each of the three tubes represented a different GORE-TEX structure. One graft was fully punctured low density; another was a poker chipped tube possessing semi-puncture through the OD skin and another was the 6A resin large pore size material. Mr. Denton reported that each of these three structures had been sent for histological examination and following these results Gore would be able to determine the most appropriate structure for use as a vascular prosthesis. Further research on long-term patency was required.

[77]       On September 20, 1973, Mr. Cooper recorded in his lab book the development of a microscopic technique that allowed the examination under an optical microscope of GORE-TEX poker chipped structures "so that we can be more precise about subtle changes possible with process variables". This technique (keyed to lighting), as Mr. Cooper testified, enabled the sintered grafts to be photographed and the fibril lengths to be measured over large areas of the graft. Mr. Cooper then ordered the photography of remaining samples from previous shipments and the measurement of fibril lengths on them.

[78]       On September 13, 1973, Mr. Detton recorded a trip visit with Mr. Mendenhall to Dr. Kelly. Dr. Kelly had previously reported six small caliber (3mm) large pore size GORE-TEX grafts were patent after ten weeks.

[79]       On October 2, 1973, Dr. Detton records a visit he and Mr. Giovale had at the AHI in which he indicates "I was pleased to learn that the last series of five grafts (vascular prosthesis lot number 569-07163-1) a 4.3 mm large pore size produced an 80% patency during the initial 21-day period". He added "although this does not constitute a large series, nonetheless, it is considered an extremely favourable result as false positives are impossible to obtain within the realm of dog testing". He noted discussion of some specifics of the research format to be utilized in the second phase of tests. The research format would include utilisation of pure bred dogs.

[80]       On October 9, 1973, Mr. Detton once again visited AHI. He wrote he reviewed 15 different GORE-TEX graft structures with Drs. Goldfarb and Campbell and wrote:

This review was a most meaningful to date as it was possible to illustrate the various structures through 60x microphotographs of the OD surface, ID surface and wall crosssections of each graft. During the review, it became quite obvious that appropriate histological and pathological results needed to be reviewed prior to selecting the two most appropriate grafts for inclusion in the second phase of AHI's GORE-TEX research.

He recorded that Dr. Campbell seemed to favour the utilization of smaller pore size grafts with approximate pore size in the range of 15 to 25 microns. He reported Dr. Goldfarb felt larger pore size grafts with a consistency and smaller pore structure at the ID surface was more likely to prove successful as a small caliber artificial prosthesis.

(5)             The 64 graft series

[81]       On October 11, 1973, Messrs. Detton & Green visited Drs. Goldfarb, Campbell, Gall and the pathologist Dr. Roe. Mr. Detton recorded the meeting primarily concentrated upon a comprehensive explanation of the node fibril GORE-TEX structure for Dr. Roe's benefit. He wrote there was a brief discussion regarding the next series of small caliber arterial prosthesis testing. Mr. Detton wrote he discussed with Dr. Campbell the potential of providing two different graft structures (fibril length variations). He said he also expressed his desire to provide these two structures in two wall sizes. One structure would have fibril lengths ranging from 40 to 75 microns, the other in the range of 15 to 25 microns. He said it was the general consensus of the meeting that the uses of these two structures with pure bred animals would produce the most major results to date resulting in the identity of the most appropriate structure for the development of a viable neointema. Dr. Goldfarb testified that these four structures, including the fibril distances, were suggested by him.

[82]       From a chart in a paper published in April 1974 by the American Society for Artificial Internal Organs entitled "Expanded Polytetrafluoro-Ethylene As A Small Artery Substitute" authored by Drs. Campbell, Goldfarb, Roe, Dietrich and Mr. Detton reporting on the 64-graft study, the first seven grafts implanted in this series took place on October 17 and 18, 1973, prior to the involvement of Mr. Shanti Mehta, from Gore, who, on October 22, 1973, travelled to Flagstaff when Mr. Detton explained to him the results to date of Dr. Goldfarb's experiments.

[83]       On October 23, 1973, Messrs. Mehta, Mendenhall and Detton met with Drs. Goldfarb, Campbell and Gall where agreement was reached upon a specific research protocol for the 64-graft series. Two wall sizes were chosen; one (known as thick) at 32 mils (approximately 0.7 mm thick) and the other at 20 mils (approximately 0.5 mm) (known as thin) with two ranges of variable pore sizes (or fibril lengths); fine, with a pore size of 5 to 30 microns and coarse, with a pore size of 40 to 75 microns. Sixteen dogs were in the experiment.

[84]       On October 26, 1973, Mr. Detton recorded a visit with Dr. Volder at the University of Utah. He wrote agreeing to provide Dr. Volder with graft materials composed of large pores (50 to 70 microns) and thin walls (20 mils).

[85]       On November 16, 1973, Mr. Detton recorded a trip visit to Dr. Cohn in Boston where a small calibre arterial prosthesis project was being conducted. He reported the research was meaningful but their results were "no more favourable than those of the Arizona Heart Institute" and the communication problem existing between Flagstaff and Boston had, moreover, left Peter Ben Brigham in a position of doing experiments which were already antiquated by technical advances in Flagstaff. He noted the research at AHI was a full step ahead of the efforts at Peter Bent Brigham.

[86]       On December 11, 1973, Messrs. Detton and Mendenhall visited the AHI to review the results to date of the 64-graft experiment. At the time, 20 of the 64 grafts had been implanted displaying indications thus far of 100% patency rate. Mr. Detton records Dr. Campbell having expressed a clear preference for the fine/thin structure as he found the suturability and handling superior to any prosthesis material that he had previously experienced.

[87]       Mr. Detton recorded learning from Dr. Campbell the results of a second experiment involving the placement of 18 GORE-TEX grafts involving only the fine/thin structure and the coarse/thin structure with the fine/thin structure displaying patency and the coarse/thin graft displaying some clot formation at the suture line.

[88]       On December 14, 15, 1973, Dr. Volder visited AHI at Gore's expense to exchange information and on January 3, 1974, Mr. Detton visited Dr. Goldfarb. In a trip report he said he provided Dr. Goldfarb with photomicrographs for all structures provided by Gore to AHI to that time to "enhance their ability to provide accurate patency and histological results".

[89]       On January 8, 1974, Dr. Goldfarb prepared the final draft of the ASAIO paper to be presented on April 27, 1974, summarizing the results of the 64-graft series. He wrote: (p.48)

Grafts made of expanded Teflon were interposed in the carotid and femoral arteries in dogs. All were 4 mm in diameter and 4 cm in length, with varying wall thickness (0.8-1.2 mm), density (.30-.32 gm/ml) and pore size (5-30 microns). No heparin was administered. Follow/up exceeds 2 months. Of 60 implantations, 36 grafts were harvested and submitted for histological study. The remaining are in living animals with pulses over the grafts.

80% of the harvested grafts were patent. Occlusion in four was possibly due to technical error recorded at the time of implantation. Histological examination of patent grafts demonstrated fibroblastic ingrowth, capillary formation and the development of uniform smooth neointima throughout the length of the graft and over the suture line.

[90]       On February 19, 1974, Mr. Detton prepared a report entitled "GORE-TEX Medical Products Developments: A Summary of Current Research Findings" (D-246) which he submitted to the senior officers of Gore. He acknowledged research on a small caliber vascular prosthesis was concentrated at AHI, the University of Utah (Dr. Volder, Dr. Kelly et al.) And at Peter Brent Brigham in Boston. He noted for the AHI there were two inter-related experiments, the 64-graft experiment and a second experiment involving 107 grafts.

(6) Subsequent developments

[91]       On March 1, 1974, Dr. Goldfarb for the first time by him implanted a GORE-TEX graft into a human which proved to be successful. Dr. Goldfarb testified that during surgery, he discovered a narrower graft was required from the one he had requested on February 26, 1974 from Mr. Green which had specifications of internodal distance (10 to 20 microns), a wall thickness of 0.5 mm and an internal diameter of 18 to 20 mm. He said he had to use some of the 8 mm internal diameter tubing he had previously received from Mr. Green which had the "Goldfarb Structure". He said he inspected the graft under a microscope to insure that its structure met his specifications and he said it did. However, Dr. Goldfarb did not record the structure of the graft used.

[92]             Thereafter, Dr. Goldfarb says he continued to successfully implant "ePTFE vascular grafts in humans".

[93]       On April 2, 1974, Mr. Cooper's U.S. patent application was filed. Mr. Cooper's patent application was almost a verbatim copy of Mr. Detton's February 1974 report describing Dr. Goldfarb's' work as well as the work of others.

[94]       On April 27, 1974, as noted, Dr. Campbell presented to the ASAIO meeting the results of the 64-graft series. The paper disclosed an overall patency of 78% in grafts of 5 to 112 microns pore size and 0.3 to 0.75 mm wall thickness. In grafts with a fibril length (pore size) smaller than 34 microns, a 96% patency rate was noted.

[95]       At that same meeting, Dr. Volder presented a paper which also discussed fibril lengths within the scope of the patent application filed by Mr. Cooper.

[96]       In June 1974, Mr. Green and Mr. Mendenhall left their positions with Gore. They, Dr. Goldfarb and others formed a company called IMPRA to manufacture grafts.

[97]       On October 24, 1974, Dr. Goldfarb filed his U.S. patent application.

[98]       In late 1983, Dr. Goldfarb, in the context of legal proceedings initiated in the United States, retrieved the original paraffin blocks of the ePTFE grafts experiments he had conducted in 1973 and 1974 and asked Walter Catron, his research assistant at the time, to prepare histological slides from them. As a result in early 1984, Dr. Goldfarb conducted a microscopic evaluation of the slides made from the 1973 and 1974 grafts preserved in the paraffin blocks. He measured the internodal distance of these slides. He said his observations confirmed his unwritten fibril length observations in 1973, pre and post implant.

[99]       In 1988, during his U.S. deposition, Dr. Goldfarb, in the presence of Gore's counsel and Gore's experts, conducted a second microscopic evaluation of those slides. Dr. Goldfarb maintains that these evaluations confirm his 1973 and 1974 internodal distance measurements.

ANALYSIS

(a)             The applicable principles

[100]    The critical issue in this trial is to determine the date of the invention, in this case, the discovery of the range of appropriate internodal distances or fibril lengths between the nodes in the internal structure of ePTFE tubing for use as an artificial vein or arterial replacement graft in humans.

(i)          Date of invention

[101]             "Invention" is defined in section 2 of the Act in the following terms:

"invention" means any new and useful art, process, machine, manufacture or composition of matter, or any new and useful improvement in any art, process, machine, manufacture or composition of matter;		« invention » Toute réalisation, tout procédé, toute machine, fabrication ou composition de matières, ainsi que tout perfectionnement de l'un d'eux, présentant le caractère de la nouveauté et de l'utilité.

[102]    What must be proven to establish a date of invention prior to its filing date is set out in the Federal Court of Appeal's judgment in Koehring Canada Ltd. v. Owens-Illinois Inc. (1980), 52 C.P.R. (2d) 1 at page 11 where LeDain J.A. (as he then was), stated:

     To establish a date of invention prior to the filing date of an application it is necessary to be able to show that the invention was reduced to a practical and definite shape either by written or oral description of it that would enable a person skilled in the art to make it or in the case of an apparatus, by the apparatus having been actually made....

[103]             Koehring Canada Ltd., supra, also reiterated the principle that to establish a date of invention prior to the date of filing, it was not necessary to have made an embodiment of it because Canadian patent law does not require a reduction to practice.

[104]    The Supreme Court of Canada in Christiani and [1929] S.C.R. 443">Nielsen v. Rice, [1929] S.C.R. 443, which was referred to by Justice Le Dain in Koehring Canada Ltd., supra, elaborated on the meaning of the date of discovery of the invention and also touched upon the necessity of disclosure. Justice Rinfret said this at page 456 of the reported case:

     The holding here, therefore, is that by the date of discovery of the invention is meant the date at which the inventor can prove he has first formulated, either in writing or verbally, a description which affords the means of making that which is invented. There is no necessity of a disclosure to the public. If the inventor wishes to get a patent, he will have to give the consideration to the public; but, if he does not and if he makes no application for the patent, while he will run the risk of enjoying no monopoly, he will none the less, if he has communicated his invention to "others," be the first and true inventor in the eyes of the Canadian patent law as it now stands, so as to prevent any other person from securing a Canadian patent for the same invention. [emphasis mine]

[105]    The ultimate finding of the Supreme Court of Canada in Christiani and Neilsen, supra, is expressed by Justice Rinfret at pages 456 and 457:

     Coming now to apply these guiding principles to the facts of this case, we find that the commission evidence taken in Denmark establishes that in 1921 -- almost a year before the earliest date to which [1929] S.C.R. 443">Rice's invention can be carried back -- Bayer conceived the idea, disclosed it to "others" . . ., instructed experiments, made some on his own account and produced porous cement. Therefore, he had invented the process.

                          . . .

     Bayer invented a new principle and a practical means of applying it. He "was not bound to describe every method by which his invention could be carried into effect". ... The conception of the idea "coupled with the way of carrying it out" ... and "reduced to a definite and practical shape" ...constituted the invention of his process, which he communicated to others.

[106]             Koerhing Canada, supra, is also authority for the proposition as to when an invention is completed. An invention is complete if the disclosure would enable the person skilled in the art to make the invention defined by the conflict claims without the exercise of inventive ingenuity. What this means, in my view, is that functional problems with a purported invention, as first made or reduced to practice and disclosed, which needed to be resolved by the exercise of inventive ingenuity, i.e. by a further inventive discovery will push forward in time an alleged date of invention.

[107]    In Lubrizol Corp. v. Imperial Oil Ltd. (1990), 33 C.P.R. (3d) 1, the Federal Court of Appeal stated a date of invention can be proven, in the case of an apparatus, as of the date when it was actually made or, where a process is involved, when it was used. The essential fact to be proven is that, at the asserted date, the invention was no longer a mere idea that floated through the inventor's brain but had been reduced to a definite and practical shape.

(ii) Utility

[108]    The concept of utility is incorporated into the definition of "invention" in section 2 of the Act through the term "useful".

[109]    The Supreme Court of Canada in [1981] 1 S.C.R. 504">Consolboard Inc. v. MacMillan Bloedel (Sask.) Ltd., [1981] 1 S.C.R. 504, discussed this concept. Dickson J., as he then was, explored, at page 525, the meaning of "not useful" in patent law. He said, quoting from Halsbury's Laws of England, (3rd ed.), vol. 29, at page 59:

It means "that the invention will not work, either in the sense that it will not operate at all or, more broadly, that it will not do what the specification promises that it will do".

[110]    As I see it, the test of utility or usefulness reflects the notion that what is patented will work. Chief Justice Jackett in Procter & Gamble Co. v. Bristol-Myers Canada Ltd., 42 C.P.R. (2d) 33 (F.C.A.) expressed himself this way at page 39:

. . . as I understand the learned Judge's finding on the facts, it is that Dr. Armstrong did not "know" the invention in question in 1952 because he did not learn from his tests that fabrics could be satisfactorily conditioned in the dryer. By definition an "invention" includes a "new and useful process".⁷ A "new" process is not an invention unless it is "useful" in some practical sense. Knowing a new process without knowing its utility is not in my view knowledge of an "invention". [footnote omitted]

[111]    In Procter & Gamble, supra, Chief Justice Jackett quoted the findings and conclusion of the trial judge at page 38 relating to the failed experiments:

. . . The idea was abandoned. In his examination by counsel for the defendant, he stated that it was "a good try but no success". At the time, since synthetic fabrics were not being generally distributed, he was not concerned with static electricity but merely imparting a feeling of softness to the fabrics. An unsuccessful experiment or series of experiments after which an idea is abandoned is not sufficient evidence on which to establish that a patent, which subsequently proves practically very useful, was either anticipated or lacked novelty. [emphasis mine]

[112]             Proving actual utility at the claimed date of invention is not the only way of establishing it. Canadian patent law holds, in certain circumstances, sufficient if the inventor had soundly predicted the utility of the invention at that date.

[113]    Mr. Justice Wetston in Apotex Inc. v. Wellcome Foundation Ltd., 79 C.P.R. (3d) 193 at 225 (F.C.T.D.), said this about making sound predictions with respect to pharmaceutical claims which I find useful and adopt for the date of invention in a different but similar context i.e., human application:

     The jurisprudence appears to highlight that the pharmaceutical field is as much concerned with testing and practical observation as it is with theory. Prediction on a theoretical level in the pharmaceutics field is not readily available to determine if an invention will work, unlike in the area of combining certain chemicals to produce a new compound. Rather, the emphasis is upon experimental efforts in the laboratory and the clinic. In other words, it is as much a matter of choosing the appropriate methods to test the properties of the compound accurately, and carrying out the steps of a viable research plan that an inventor, having gathered the results of the research, will be able in the end to establish a sound basis upon which to claim an invention.

[114]    On this branch of the law, Monsanto Co. v. Commissioner of Patents (1979), 42 C.P.R. (2d) 161 is authority for the proposition that the doctrine of sound prediction is not applicable where evidence demonstrates a lack of utility of the alleged invention: there can be no sound prediction of utility when an invention is shown not to work.

(iii) The true inventor

[115]    I take from the Privy Council's decision in Canadian General Electric Co. v. Fada Radio Ld., [1930] A.C. 97 at 101, the following proposition that a true inventor is a person who demonstrates inventive ingenuity. Lord Warrington of Clyffe quoted the trial judge, Maclean J., as follows:

"There must be substantial exercise of the inventive power or inventive genius, though it may in cases be very slight. . . . if the invention requires independent thought, ingenuity and skill, producing in a distinctive form a more efficient result, converting a comparatively defective apparatus into a useful and efficient one, rejecting what is bad and useless in former attempts and retaining what is useful, and uniting them all into an apparatus which, taken as a whole, is novel, there is subject matter. A new combination of well known devices, and the application thereof to a new and useful purpose, may require invention to produce it," . . . .

[116]             Justice Strayer's decision in Mahurkar v. Vas-Cath of Canada Ltd. (1988), 18 C.P.R. (3d) 417 (F.C.T.D.), is authority for the proposition that a person's skill and knowledge are relevant in determining whether that person is the true inventor, particularly with respect to inventions of a complex and technical nature. I take from Justice Teitelbaum's decision in Procter & Gamble Co. v. Kimberley-Clarke of Canada Ltd. (1991), 40 C.P.R. (3d) 1 (F.C.T.D.), the proposition that a person presenting a problem for solution is not an act of invention. There must be evidence that the inventor had a significant role in solving the problem. Justice Teitelbaum said this at page 54:

     After reviewing the evidence, I am satisfied that what Keasling did was what any person with a problem would do. He went to a company, in this case Raychem, that he thought might be able to help him and presented the problem. There is no evidence that Keasling had a significant role in solving the problem in elasticizing portions of garments. On the other hand, what is clear is that Althouse with his "bank of knowledge" of heat-shrinkable materials came up with the solution to the problem and, consequently, the invention. [emphasis mine]

(iv) Evidentiary matters

[117]    I take from Hammond Organ Co. v. Stinson Jr. (1970), 65 C.P.R. 62, the evidentiary principles in patent conflict cases, that (1) the onus of proof that the appellant had made the invention and the date by which he made it was upon him; (2) the desirability of supporting evidence (corroboration) in terms of particular diary sketches, experimental records and by disclosure. (See also [1967] S.C.R. 196">Traver Investments Inc. et al. v. Union Carbide Corporation, [1967] S.C.R. 196.

DISCUSSION

(a)             What is the invention and its context

[118]    The first step in the analysis to determine who, as between Dr. Goldfarb and Mr. Cooper, was the first inventor of a successful artificial small vascular human vein or artery replacement, is to define exactly what the invention is.

[119]    The invention relates to an artificial vascular prosthesis made from ePTFE. The properties and method of manufacture of ePTFE are not new. They are prior art. Robert Gore was the inventor and obtained, in 1976, a patent on that invention.

[120]    What was not known in 1970, however, was whether ePTFE tubing could have a medical use. Experimentation or search for use for it as a vascular graft in replacement for natural arteries and veins in humans began almost immediately after Mr. Gore filed his U. S. patent application in 1970.

[121]    The invention, an appropriate range of fibril length in the material, is what made the ePTFE tubing useful for such purpose. The essential feature of the invention is the distance between the nodes (or the length of the fibres connecting them) which forms part of the internal structure of ePTFE tubing.

[122]    An appropriate fibril length is what permits this ePTFE tubing to act as a useful artificial graft which remains patent because it allows cellular or fibroblastic movement and thus tissue ingrowth.

[123]    In this context, I agree with the plaintiff's formulation that the ultimate issue is for me to decide who, as between Dr. Goldfarb and Mr. Cooper, first determined, with a reasonable expectation of success, the fibril lengths that would produce grafts which would permit tissue ingrowth and thus remain patent.

(b)             The suggested dates of invention

[124]    It will be recalled the Commissioner decided the date of invention: (1) was May 19, 1973, for claims C-1 to C-4. May 19, 1973, is when Gore held its Open House in Flagstaff, Arizona. These claims were awarded to Gore; (2) the date of mid-July 1973, for the four claims C-5 to C-8 which the Commissioner awarded to Dr. Goldfarb. Mid-July 1973 is said to be when Dr. Goldfarb first conducted the 64-graft experiment.

[125]    The Commissioner, in his decision, did not elaborate why and on what basis he determined these dates of invention for the various conflict claims he had drafted.

(i) By the plaintiff

[126]    The plaintiff, Dr. Goldfarb, says the Commissioner's determination of the date of invention for all of the conflict claims is wrong. Dr. Goldfarb offers several alternative dates of invention in the following priority:

(1)             February 8, 1973, when, according to his testimony, he disclosed the invention -- the desired internodal distance -- to Messrs. Cooper and Mendenhall during a meeting held that day. As noted, Dr. Goldfarb testified, after receiving GORE-TEX tubing before the meeting, he reviewed its internal structure and realized tissue would ingrow between the solid ePTFE nodes and the fibrils, which interconnect those nodes, appeared to be quite thin and flexible and capable of moving to allow cells to pass through by being pushed apart;

(2)             May 23, 1973. This is the date of Dr. Goldfarb's first patency in a dog of a graft made of ePTFE tubing. It occurred in his first experiment on ePTFE GORE-TEX tubing. He harvested a second patent graft on June 7, 1973 and a third patent graft on June 13, 1973. Counsel for the plaintiff urges upon me that by May 23, 1973, Dr. Goldfarb had established all of the parameters required for a successful vascular prosthesis of ePTFE tubing including the relevant fibril length range. By May 23, June 7, and June 13, 1973, Dr. Goldfarb, it is advanced by his counsel, not only established his invention of the proper fibril length range but had also tested the range to confirm his conception. By that date, Dr. Goldfarb, it is said, clearly established that grafts with fibril lengths falling within his range would be useful as small artery prostheses in humans;

(3)             May 31, 1973. Dr. Goldfarb testified, when Mr. Mendenhall visited him a second time in May 1973, he expressed to him what he felt were the correct specifications for a successful small artery vascular graft in humans. He testified he told Mr. Mendenhall the internodal distance of the material had to be between five and about 100 microns with a preferred internodal distance of 20 to 30 microns, a wall thickness of .25-.75mm as well as be compliant and flexible. Dr. Goldfarb further testified he explained to Mr. Mendenhall these appeared to be the appropriate specifications for the good healing of the graft, good tissue infiltration encapsulation allowing the development of a satisfactory neoenthima based on a structured endothelial cellular layer. Counsel for the plaintiff urges, by the end of May 1973, Dr. Goldfarb disclosed to Mr. Mendenhall the importance of internodal distance, the lower limit of the appropriate internodal distance range (5 microns) as well as the upper limit of 100 microns. It is urged this disclosure was clearly sufficient to enable one skilled in the art to put the invention into practice without undue research and experimentation i.e. without any further exercise of inventive skill;

(4)             June 21, 1973. June 21 is the last day of spring. Dr. Goldfarb testified, in the spring of 1973, likely in June 1973, he met with Dan Detton in a restaurant in order to discuss his specifications for an ePTFE graft structure. As was noted, Dr. Goldfarb said he transcribed his specifications (internodal distance greater than 5 microns to about 100 microns, wall thickness of .25 to .75mm, good uniformity, good compliance, flexibility) on a piece of paper which was given to Mr. Detton. Dr. Goldfarb also testified, shortly after giving this piece of paper to Mr. Detton, perhaps even the following day, he received a telephone call from Harold Green who wanted to find out more directly and more precisely what it was that Dr. Goldfarb needed. Dr. Goldfarb testified, during this telephone call with Mr. Green, he reiterated the specifications he had given to Messrs. Mendenhall and Detton.

[127]    Dr. Goldfarb says there are two other events which confirm his invention. First, Dr. Goldfarb conducted a second series of dog implants in July 1973, with the assistance of Dr. Campbell. This second series produced many successful patent grafts which demonstrated the desired tissue ingrowth.

[128]    This second series produced seven patent grafts out of ten beyond the 21-day test. Mr. Detton wrote, in a trip report, that the "pore size" of these grafts was approximately 10 to 20 microns which would, he recognized, certainly allow for both fibroblastic tissue invasion as well as capillary invasion into the interstices of the grafts.

[129]    The second confirmatory event advanced to prove Dr. Goldfarb's invention was the October 11, 1973 meeting and the resulting 64-graft series. This is when he says he provided the fibril distances for the protocol to the experiment. The results of the 64-graft series were written up on January 8, 1974 by Dr. Goldfarb in the ASAIO abstract and resulted in a paper delivered on April 27, 1974.

(ii) By the defendant

[130]             Counsel for the defendant, Mr. Cooper, put forward the position the Commissioner was incorrect in establishing the date of May 19, 1973 as the date of Mr. Cooper's invention. The Commissioner should have determined the date of invention of May 1, 1973 when Mr. Cooper noted in his lab book the fibril distances from the Kelly slides. Moreover, the Commissioner was wrong in selecting February 1974 as the date of invention for conflict claims C-5 to C-8 and awarding them to Dr. Goldfarb.

[131]             Counsel for Mr. Cooper relies on the following facts:

(1)             In November 1972, Mr. Cooper sent out the samples for the three structure experiment;

(2)             He predicted to Dr. Eiseman in November 1972 that lot 416-11172-10 would allow more cell ingrowth;

(3)             On April 17, 1973, Dr. Kelly sent a slide which showed that lot 416-11172-10 had allowed cell ingrowth;

(4)             Almost simultaneously, Dr. Sharp returned his results from the "Three Structure Experiment" showing that the lot with largest pore size, lowest bubble point, had tissue ingrowth and patency, a report which Mr. Cooper acknowledged on April 19, 1973;

(5)             Harold Green testified that poker chipped tubes with the density range in the three structure experiment could have fibril lengths above 50 microns;

(6)             Upon receipt of the Kelly slide and Sharp results, Mr. Cooper, on April 22, 1973, viewed the slide with Messrs. Giovale and Davee; on April 23, 1973, he photographed the Kelly slides and had Mr. Green make further photographs of it.

(7)             On May 1, 1973, he measured the fibril length of the Kelly slide and made his notebook entry. A few days later, he visited a pathologist to discuss that slide. Mr. Cooper then recorded other experiments in his laboratory notebook to try to manufacture grafts with the correct fibril length;

(8)             The Kelly slides, together with a photograph of a Gore prosthesis before implantation and a scale to determine its fibril length, was exhibited at Gore's Open House on May 19, 1973;

(9)             Finally, his counsel said Mr. Cooper succeeds in finding a technique to photograph fibril length of the sintered products using a light microscope and all samples thereafter are shipped with photomicrographs showing fibril length.

[132]             Counsel for Mr. Cooper urges upon me that, based on the quality of the evidence, the existence of independent documentary evidence and plausibility, Mr. Cooper's evidence should be preferred and his date of invention accepted over Dr. Goldfarb's.

CONCLUSIONS

[133]    Before setting out my reasons for accepting or rejecting the suggested dates of invention put forth by the plaintiff and the defendant or maintaining the Commissioner's findings, it is useful to compare, in respect of the invention, what Mr. Detton wrote in his February 1974 report and what Mr. Cooper wrote in his April 1974 U.S. patent filing where he mentioned four experiments.

[134]    I find the wording describing the experiments in Mr. Cooper's U.S. patent filing to be substantively and textually similar to Mr. Detton's description in his February 1974 report (as they relate to artificial vascular prostheses). It is obvious to me Mr. Cooper (or his patent agent) lifted the description of the experiments in the U.S. application from the text of Mr. Detton's 1974 report. The significance of this wording identity is not as important as in its content and the fact it found its place in Mr. Cooper's application. It is interesting to note that Mr. Cooper's application does not mention Dr. Sharp's work.

[135]             Example number one comes under the heading Arizona Heart Institute, in Mr. Detton's report. Example number two comes under the description of research done at the University of Utah by Dr. Volder on sheep. Example number three of Mr. Cooper's filing application is born out of the research conducted at Peter Bent Brigham Hospital -- Harvard Medical School. Mr. Cooper's fourth example is not found under the heading in Mr. Detton's February 1974 report called "GORE-TEX Small Caliber Vascular Prosthesis Research" but rather under a heading in that report called "GORE-TEX Large Caliber Vascular Prosthesis". The description under experiment number four finds its place under research being done at the Arizona Heart Institute.

[136]    I further find that in Mr. Cooper's example number one to his U.S. filing, the reference to the 64 implantations relates to the 64-graft experiment conducted by Dr. Goldfarb in 1973.

(a)             February 8, 1973

[137]    I reject Dr. Goldfarb's proposed February 8, 1973 date of invention and this for three reasons. First, in his supporting affidavit in the Conflict Proceedings in Canada, Dr. Goldfarb did not mention the disclosure of his specifications on that date. Mr. Mendenhall made no note of it and Mr. Cooper denied the disclosure. Second, Dr. Goldfarb's alleged disclosure on February 8, 1973, is inconsistent with his later testimony that he disclosed the specifications to Mr. Mendenhall in May 1973 and to Mr. Detton in June 1973. Why would he disclose it a second time to Mr. Mendenhall if he had done so before. Third, Dr. Goldfarb had not experimented with ePTFE tubing before. This was new material for him. He had, in my view, an idea that it might work as an artificial vascular graft as replacement for small veins and arteries in humans but he did not know it would work because he had done no testing.

(b)             May 23, 1973

[138]    I do not accept Dr. Goldfarb's alternative date of May 23, 1973 when, in his first series of experiments with 21 grafts of ePTFE tubing made by Gore implanted in seven different dogs he obtained his first patency. The problem with the first series is that only three of the twenty-one grafts were patent; the rest failed for various reasons.

[139]    On this basis, it could not be said Dr. Goldfarb had enough information to lead him reasonably to conclude his invention would work.

[140]    I accept that at the time he began his first series with experiments in GORE-TEX tubing in April 1973, Dr. Goldfarb knew the tubing specifications he wanted and he implanted those in the experimental animals.

[141]    I would not have made this finding on the basis of Dr. Godlfarb's testimony alone to the effect he, before and after implant, made measurements of the fibril lengths in the tubing. The problem is Dr. Goldfarb never made recordings of his measurements and there is no mention of such measurements on the autopsy sheets maintained by Mr. Moore. Some corroboration was necessary.

[142]    What saves the day for Dr. Goldfarb, in my view, is that he preserved the grafts, coming out of this 1973 experiment, in paraffin blocks from which histological slides were made in the early 1980s. Dr. Goldfarb then measured the fibril lengths from these grafts, recorded his observations in 1984 which confirmed his 1973 specifications. He did the same in 1988 in the U.S. discovery proceedings.

[143]             Viewing this evidence and that of Mr. Catron's, I am of the view when Dr. Goldfarb began his first experiment on ePTFE tubing he knew what he wanted in terms of fibril length, a fact confirmed by the fibril lengths he actually selected for such experiment.

[144]             However, as noted, this first series did not permit Dr. Goldfarb to really know his fibril specifications would work in GORE-TEX tubing. While Dr. Goldfarb might have been on the right track, he could not reasonably know he was with the new ePTFE tubing he was just beginning to experiment on. I would classify his first series as a failed experiment (see Procter and Gamble (F.C.A.), supra.

(c)             May 31, 1973

[145]    I reject May 31, 1973 as an invention date arising out of his disclosure to Mr. Mendenhall. Dr. Goldfarb's testimony, while not disbelieved, was not corroborated. Mr. Mendenhall did not testify in these proceedings.

[146]    In any event, by May 31, 1973, Dr. Goldfarb had not established utility nor had a sound basis for predicting GORE-TEX tubing would be useful as a small artificial vascular graft.

(d)             June 21, 1973

[147]    While Mr. Green corroborated Dr. Goldfarb's testimony that he had disclosed his specifications to Mr. Detton in the spring of 1973 when he wrote them down on a napkin and he, Mr. Green, called back a few days later to confirm exactly what kind of tubing he required, I do not attach any weight to Mr. Green's evidence on this point for the following reasons: First, Mr. Detton did not testify in this proceeding. Second, Mr. Green was heavily involved with IMPRA. Third, Dr. Goldfarb initially had sworn in his affidavit Mr. Green had called him sometime in July 1973, not June 1973.

(e)             Mid July 1973

[148]    The Commissioner found first inventorship to Dr. Goldfarb for claims C-5 to C-8 based on a date of mid July 1973 for the 64-graft series which is the period Dr. Goldfarb had indicated in his conflict affidavit. The problem is that the 64-graft series began in October 1973.

(f)             The established date of invention for Dr. Goldfarb

[149]             Considering the evidence as a whole, I am satisfed Dr. Goldfarb has established a date of invention, at the latest, of August 7, 1973 when the third set of patencies were obtained during the second series of experiments performed at AHI. In particular, the fibril length measurements done in 1984 and 1988 confirm Dr. Goldfarb and Dr. Campbell, under his instructions, implanted grafts with his specifications as to fibril length. Moreover, the success in patencies shows, in my view, Dr. Goldfarb had crossed the line to now reasonably know his fibril length specifications would now work in ePTFE tubing.

[150]    In this context, I accept Dr. Goldfarb's evidence that the 64-graft experiment which produced high patency rates was confirmatory of his earlier results obtained at the end of July, early August 1973 and that he provided the fibril length and other specifications for that experiment.

(g)             What about Mr. Cooper's date of invention?

[151]             Counsel for Mr. Cooper argues for a date of invention of May 1, 1973, the Commissioner having found May 19, 1973.

[152]    I have concluded that the evidence before me establishes neither invention date. I base my conclusion on the following findings and considerations.

[153]    First, while counsel for Mr. Cooper produced many documents evidencing research being conducted on GORE-TEX made artificial vascular grafts for small vein and artery replacement, none disclose the fibril length prior to May 1, 1973 and Mr. Cooper admitted he had not focussed on fibril length before May 1, 1973.

[154]    In this context, I am satisfied the "Three Structure Experiment" launched by Gore in late 1972 was not designed to measure internodal distance because knowing the pore size measured by ABP does not aid in knowing fibril length so testified Mr. Giovale and confirmed by Mr. Green. They said a poker chipped structure, where the nodes ran from outer diameter to inner diameter, had nothing to do with their spacing.

[155]    In any event, in fact, none of the grafts in the "Three Structure Experiment" conducted by outside researchers were measured for fibril length including Dr. Sharp's slides when in February 1973 he reported patency. Dr. Sharp followed up with his final report on April 2, 1973, but Mr. Cooper did not measure the internodal distance of those grafts. Dr. Sharp's slides were filed away.

[156]    I am satisfied, on the whole of the evidence, Mr. Cooper did not invent anything on May 1, 1973. He, at best, simply measured the internodal distance on the Kelly slides of grafts which had failed and could not appreciate at that time the key that fibril length played in a patent graft. He measured the non patent Kelly grafts but did not measure, and he should have based on Dr. Sauvage's evidence, the patent Sharp grafts.

[157]    I am driven to this conclusion by (1) the wording of his laboratory note which simply records the fibril length but draws no conclusion; (2) there is no evidence he disclosed his invention to anyone: he never told Dr. Kelly about it, neither did he inform Mr. Green or Mr. Giovale who were in charge of manufacturing at Gore; (3) but more importantly, he did not, during this period of time, effect a change in manufacturing GORE-TEX graft to include his invention (4) the shipping logs were not subsequently altered to reflect the internodal distances of the grafts being shipped; (5) his lab book was not provided to Mr. Uebler, Gore's patent attorney in August 1973 and his response to Mr. Uebler (quoted at paragraph 74 of these reasons) does not focus on why fibril length is important but simply that "fibrils may encourage rapid tissue growth".

[158]    In my view, the May 19, 1973 date selected by the Commissioner (the Gore Open House) does not disclose an inventive act. First, the reasons I have discarded the May 1, 1973 date apply and, in addition, there is no indication fibril length is important in the material displayed namely in part Dr. Kelly's failed graft.

[159]    All of the evidence suggests to me that Mr. Cooper only realized the key to a successful ePTFE graft -- the appropriate internodal distance -- only came to him after he received Mr. Detton's report in 1974, as the Commissioner found.

DISPOSITION

[160]    For all of these reasons, the plaintiff, Dr. Goldfarb, succeeds in these proceedings and W.L. Gore & Associates fails. Costs are awarded to the successful plaintiff and they may be spoken to. As a result, the Commissioner shall award conflict claims C-1 to C-8 to Dr. Goldfarb.

       "François Lemieux"         

                                                              

J U D G E             

OTTAWA, ONTARIO

FEBRUARY 9, 2001