This appeal involves a patent interference that is before us for the second time. Peter B. Cooper and David Goldfarb originally filed their patent applications in 1974. An interference was declared between the applications in 1983, and the Board issued a final decision in 1995, awarding priority to Goldfarb. The Board determined that, although Cooper was the first to conceive the invention at issue, which relates to the fibril length of certаin material used for vascular grafts, Goldfarb was the first to reduce the invention to practice.
Cooper v. Goldfarb,
Cooper appealed the Board decision to this court. We affirmed the Board’s determination that Goldfarb was the first to reduce the invention to prаctice.
Id.
at 1331,
BACKGROUND
I.
The invention at issue relates to an artificial vascular prosthesis made from expanded polytetrafluoroethylene (“ePT-FE”). 1 The invention is useful as a vascular graft. In the early 1970s, when the invention was made, ePTFE was produced as tubes that had a structure consisting of solid nodes of PTFE connected by thin PTFE fibrils. The distance between the nodes is referred to as the fibril length. This distance is important to the suitability of the ePTFE material for use as a vascular graft.
The count defines the invention as follows:
An artificial vascular prosthesis comprising expanded, porous, рolytetrafluoroe-thylene having a microstructure consisting of nodes interconnected by fibrils which permits tissue ingrowth, wherein said fibrils are about above 5 microns up to 100 microns in length.
Cooper I,
During the time period at issue, Cooper was the Plant Manager of W.L. Gore
&
Associate’s (“Gore’s”) Flagstaff, Arizona facility, and primarily was involved in making ePTFE tubes. Cooper provided the tubes to various researchers, who evaluated their suitability for vascular grafts. During the course оf his work, Cooper discovered that material from ePTFE tubes with fibril lengths within the scope of the interference count was suitable for use in vascular grafts. The Board found that Cooper had conceived the invention as of June 5, 1973.
Id.
at 1328,
During the same period, Goldfarb was Director of Research and Clinical Staff Surgeon at the Arizona Heart Institute, and was conducting research on artificial vascular grafts. Between February and April of 1973, Cooper sent Gоldfarb a number of ePTFE tubes to use in his research. Although Cooper intended that Goldfarb use the tubes for vascular grafts, Cooper did not have any right of control over Goldfarb’s research, and Goldfarb was not required to use the tubes supplied by Cooper or to perform his experiments in any particular way.
Goldfarb conducted a series of experiments involving 21 grafts made from the tubes Cooper provided. On June 13, 1973, the graft labeled “2-73 RF,” which came from Lot 459-04133-9 provided by Cooper, was determined to be a successful implant in a dog. Goldfarb testified before the Board that in July of 1973 he measured the fibril lengths of that graft, which were found to be within the scope of the interference count, and observed that there was tissue ingrowth into the graft. The Board determined that Goldfarb had conceived the invention “by at least July of 1973,” and had reduced the invention to practice “by July of 1973.”
Id
. at 1329,
II.
When Cooper sent the Lot 459-04133-9 material to Goldfarb, he had not yet recognized the importance of the fibril length required by the interference count,
i.e.,
he had not yet conceived the invention, and he was not aware of the fibril lengths of the material he was sending to Goldfarb. After Cooper conceived the invention, he did not communicate his conception to Gold-farb, and he did not ask Goldfarb to use
In view of these facts, the Board, on remand from this court, determined that Cooper was not entitled to benefit from Goldfarb’s work in reducing the invention to practice.
Cooper II,
slip op. at 16. The Board first considered the relationship between Cooper and Goldfarb. The Board noted that the relationship was not like that in the typical inurement case, where the work of an employee, fellow employee, or agent inures to the benefit of the inventor.
Id.
at 9-12. The Board noted that Goldfarb was not an employee or fellow employee of Cooper, and that Cooper had no right to control Goldfarb’s work.
Id.
The Board recognized that inurement was found in
Burroughs Wellcome Co. v. Barr Laboratories, Inc.,
The Board determined that Cooper had intended that Goldfarb use the material for vascular grafts, but that he “could not have been requesting that Goldfarb reduce the invention to practice because at that time Cooper did not know what the invention in issue was.” Id. аt 15. The Board commented on Cooper’s failure to communicate his conception to Goldfarb, as well as his failure to ensure that Goldfarb used grafts with fibril lengths within the scope of the interference count. Id. The Board determined that Cooper did not know whether the material sent to Goldfarb fell within the scope of the count. Id. at 16. The Board concluded that, under these circumstances, Goldfarb’s reduction to practice did not inure to Cоoper’s benefit. Id. Cooper appeals the Board’s decision. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(4)(A).
DISCUSSION
I.
When two patent applications are directed to the same invention, the Patent Office declares an “interference” between the applications to determine which applicant is entitled to priority of invention.
See
35 U.S.C.A. § 135 (West Supp.2000). The precise scope of the interfering subject matter is defined by the interference “count.” 37 C.F.R. § 1.601(f) (2000). Priority is generally awarded to the applicant who was first to reduce the invention to practice; however, an applicant who was first to conceive the invention but last to reduce it to practice will be awarded priority if he demonstrates reasonable diligence in his reduction to practice. 35 U.S.C.A. § 102(g) (West Supp.2000). “Conception is the formation, in the mind of the inventor, of a definite and permanent idea of the complete and operative invention, as it is thereafter to be applied in practice.”
Cooper I,
At the time we decided
Cooper I,
the Board had determined that Cooper was first to conceive the invention at issue, but that Goldfarb was first to reduce the invention to practice.
Cooper I,
154 F.3d at
“Inurement involves a claim by an inventor that, as a matter of law, the acts of another person should accrue to the benefit of the inventor.”
Cooper I,
II.
Cooper challenges the Board’s decision on two grounds. First, he argues that the Bоard placed too much weight on the fact that he had not conceived the invention when he sent the Lot 459-04133-9 material to Goldfarb. Second, he contends that the Board erred when it determined that the relationship between Goldfarb and himself did not support his inurement claim. We address these arguments in turn.
A. Cooper argues that the relative timing of his conception and his sending the Lot 459-04133-9 material to Goldfarb is irrelevant to his inurement claim. He asserts that there is no authority for what he reads as the Board’s requirement that he must have conceived the invention before he sent the material to Goldfarb for testing. Cooper argues that because he conceived the invention before Goldfarb reduced it to practice in the course of testing the material at his (Cooper’s) request, he (Cooper) is entitled to the benefit of Gold-farb’s reduction to practice.
To the extent that the Board’s opinion can be read as requiring, for an inurement claim, that the inventor have conceived the invention before he asks another person to test the material relied upon to establish reduction to practice, it is incorrect. Nothing in our interference case law imposes such a requirement. Both Cooper and Goldfarb cite
Burroughs Wellcome
and
Gianladis v. Kass,
B. Cooper’s second argument is that the Board’s inurement analysis placed too much emphasis on the relationship between Cooper and Goldfarb, and overlooked the core inurement inquiry: whether Goldfarb was working at Cooper’s request when he reduced the invention to practice. Cooper asserts that the Board erred by finding no inurement because he did not have a right to control Goldfarb’s work. Cooper also asserts that, in reaching its decision, the Board should not have relied on his failure to communicate his conception to Goldfarb.
As set forth above, in order to establish reduction to practice, the inventor must prove that he made an embodiment of his invention that met all of the limitations of the interference count and that he determined that the invention would wоrk for its intended purpose.
Cooper
/,
As to whether Cooper can obtain the benefit of Goldfarb’s recognition that thе material worked for the intended purpose of the invention, there are “at least three requirements that must be met before a non-inventor’s recognition of the utility of an invention can inure to the benefit of the inventor:” (1) “the inventor must have conceived of the invention;” (2) “the inventor must have had an expectation that the embodiment tested would work for the intended purpose of the invention;” and (3) “the inventor must have submitted the embodiment for testing fоr the intended purpose of the invention.”
Genentech,
Cooper had conceived the invention by the time Goldfarb evaluated the 2-73 RF graft.
Cooper I,
As to whether Cooper can obtain the benefit of Goldfarb’s knowledgе of the fibril lengths of the material Goldfarb tested, we apply a modified version of the Genentech test, and consider (1) whether Cooper had conceived the fibril length limitation of the interference count, (2) whether Cooper had an expectation that the ePTFE material that he furnished to Goldfarb had the required fibril lengths, and (3) whether Cooper submitted the material to Goldfarb for testing to determine whether it had the required fibril lengths.
.As set forth above, Cooper hаd conceived the invention, including the fibril length limitation, before Goldfarb reduced the invention to practice.
Cooper I,
Cooper argues that the second and third prongs of the Genentech test are satisfied because he knew when he sent the Lot 459-04133-9 material.to Goldfarb that it was his best ePTFE material. In making this argument, he cites the letter dated April 2, 1973, that he received from Dr. William Sharp of the Akron City Hospital in Akron, Ohio, and the April 19, 1973 letter that he sent to Goldfarb accompanying the Lot 459-04133-9 material. Dr. Sharp’s letter reported the results of his studies in dogs of four distinct groups of ePTFE material that had been provided to him by Cooper. The letter identified one of the groups as being the most promising for use as a vascular graft, and suggested that further studies includе the measurement of the porosity of the ePTFE material. As discussed above, Cooper’s April 19 letter to Goldfarb described the Lot 459-04133-9 material as “representing] the latest attempt to achieve satisfactory pa-tency rates in small artery prosthetics.”
Neither the Sharp letter nor the Cooper letter mentions fibril length. Thus, these letters do not indicate that Cooper expected that the ePTFE material that was to be tested by Goldfarb had the fibril lengths required by the interference count, or that Cooper submitted the material to Goldfarb for a determination of its fibril lengths. As noted in
Cooper I,
and as confirmed by the Sharp letter, Gooper was focusing on the porosity of the material at that time, not its fibril length.
Cooper I,
Cooper also argues that he himself knew the fibril lengths of the material sent to Goldfarb. If that were true, then he could establish reduction tо practice even though Goldfarb’s determination of the fibril lengths does not inure to his benefit. However, no evidence of record indicates that Cooper knew the fibril lengths of the material tested by Goldfarb at the relevant time, i.e., prior to Goldfarb’s reduction to practice in 1973. The only document of record demonstrating Cooper’s knowledge of the ePTFE material’s fibril lengths reflects microscopic evaluations performed in 1984 (the “1984 dаta”). Cooper argues that this evidence can be used to establish the required knowledge nunc pro tunc, but our case law does not provide for the retroactive establishment of reduction to practice.
Cooper suggested during oral argument that, in
Cooper I,
we awarded Goldfarb a nunc pro tunc reduction to practice date because the Board, whose decision on the point we affirmed, had considered the 1984 data when it determined that Goldfarb had reduced the invention to practice in 1973. This argument mischaracterizes
Cooper I.
In
Cooper I,
we found that the testimony of Richard Mendenhall and Harold Green, two Gore employees, corroborated Gold-farb’s testimony that he had determined the fibril lengths of the 2-73 RF graft in July of 1973.
Id.
at 1330,
Like Goldfarb, Cooper can rely on the 1984 data to confirm that the 2-73 RF graft met the limitations of the interference count. However, he cannot rely on that data to establish that he appreciated, in 1973, that the ePTFE material that Goldfarb tested had the fibril lengths set forth in the count. Such a use of the 1984 data would violate “[t]he rule that ... reduction to practice cannot be established nunc pro tunc.”
Cooper I,
CONCLUSION
For the foregoing reasons, the judgment awarding priority of invention to Goldfarb is
AFFIRMED.
COSTS
Each party shall bear its own costs.
Notes
. The facts set forth herein are drawn from our previous decision in Cooper I and from the Board’s findings on remand in Cooper II, which are not challenged on appeal.