Recently, the U.S. Court of Appeals for the Federal Circuit issued an opinion in Medtronic Inc. v. Teleflex Innovations SARL, Nos. 2021-2356, -2358, -2361, -2363, -2365 (May 24, 2023), affirming a holding of the Patent Trial and Appeal Board that inventor testimony regarding conception and reduction to practice was sufficiently corroborated.
Medtronic filed petitions seeking inter partes review asserting that five of Teleflex’s coronary catheter patents were invalid over U.S. Patent 7,736,355 to Itou, which Medtronic asserted was prior art under pre-AIA 35 U.S.C. § 102(e). Following institution, Teleflex argued Itou was not prior art because the claimed inventions were conceived prior to Itou’s filing date and were either reduced to practice before that date or were diligently pursued until their constructive reduction to practice. In support, Teleflex submitted testimony from its inventors and other employees and extensive documentary evidence. The Board agreed. It determined Itou was not prior art under pre-AIA § 102(e) because the claimed inventions were: (1) conceived before Itou’s September 2005 filing date, and (2) either reduced to practice for their intended purpose before Itou’s filing date or diligently pursued until their constructive reduction to practice on the filing date of the challenged patents. Because Itou was not prior art, the Board held that the challenged patents were not unpatentable. Medtronic appealed.
The Federal Circuit affirmed. It explained that a reference is prior art under pre-AIA § 102(e) if it was filed “before the invention by the applicant,” among other requirements, and that a patent owner may antedate an asserted reference by showing prior conception and reduction to practice. Medtronic did not challenge Board’s findings regarding prior conception, and the Court determined that the Board’s findings with respect to reduction to practice were supported by substantial evidence. Specifically, the Board determined that the patentee’s testing showed the claimed inventions worked for their intended purposes, and the Court declined to reweigh those findings. The Court also found that inventor testimony regarding reduction to practice was sufficiently corroborated, including by the testimony of other R&D employees and by documentary evidence including lab notebooks, internal memoranda, engineering drawings, and documents from outside patent counsel. Because the Court determined the claimed inventions were actually reduced to practice prior to Itou’s filing date, it did not reach the issue of constructive reduction to practice, and it affirmed the Board’s finding that Itou was not prior art.