Knobbe Martens
May 25, 2023

Low-Bar for Corroboration

Written byMatthew Friedrichs & Daniel P. Hughes


Before Moore, Lourie, and Dyk. Appeal from the Patent Trial and Appeal Board

Summary: Federal Circuit confirms low bar for evidence corroborating prior inventorship pre-AIA.

Medtronic filed five IPRs against patents related to catheters, relying on a single prior art reference under pre-AIA 35 U.S.C 102(e). Teleflex argued that the invention claimed by its patents predated the prior art reference because it had conceived of the claimed invention and reduced it to practice before the critical date.  Teleflex further argued that it had shown reduction to practice because its inventors had constructed an embodiment of the invention and determined that the invention worked for its intended purpose—to provide backup support for Teleflex’s catheter products.  The Board agreed with Teleflex, finding that the purpose of patents’ invention was providing backup support for an earlier version of Teleflex’s product rather than solving a particular issue that had arisen with that product. The Board further found the inventors’ declarations supported conception and reduction to practice and that their declarations were corroborated by documentary evidence.

The Federal Circuit reviewed the Board’s factual findings on reduction to practice and diligence for substantial evidence and its legal conclusions on the purpose of the invention and priority de novo. The Federal Circuit agreed that Teleflex’s inventors were aware of the intended purpose of the invention and rejected Medtronic’s arguments that the Board had interpreted the intended purpose too broadly.  The Federal Circuit further found inventor testimony provided substantial evidence to support the Board’s conclusion that the claimed invention worked for its intended purpose. Finally, the Federal Circuit found that evidence corroborating conception and reduction to practice need only support the credibility of the inventors’ story.

Judge Dyk dissented from the majority, arguing that the inventors’ testimony did not provide substantial evidence to conclude the invention fulfilled its intended purpose and, further, that Teleflex failed to corroborate the inventors’ testimony with additional evidence.

Editor: Paul Stewart