Apator Miitors Aps v. Kamstrup A/S, 887 F.3d 1293

Kamstrup petitioned for inter partes review of U.S. Patent No. 8,893,559; the Board instituted review of claims 2 and 10 citing Nielsen as a reference.
Apator (patentee) attempted to "swear behind" Nielsen by showing inventor Jens Drachmann conceived the invention before Nielsen’s effective filing date (Mar. 25, 2010).
Apator submitted Drachmann’s declaration plus emails (Feb. 15 and Mar. 22, 2010) and a set of drawings which Drachmann testified evidenced prior conception and attachment of specific files (mechanics6.png and UFM++ venture.pdf).
The emails themselves did not show attachments or identify the alleged files; the drawings bore a later modification date (Jan. 30, 2012) and relied on Drachmann’s file-naming testimony for earlier dating.
The Board found Apator offered no corroboration independent of Drachmann’s testimony and therefore failed to prove conception prior to Nielsen; it held claim 2 anticipated and claim 10 obvious in part over Nielsen and Körner.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Can Apator swear behind Nielsen by proving conception before Nielsen’s date?	Drachmann conceived prior to Nielsen; emails and drawings corroborate.	Evidence lacks independent indicia of conception; relies solely on Drachmann’s testimony.	No — insufficient corroboration; cannot swear behind Nielsen.
Do the proffered emails independently corroborate conception?	Email text referencing an attached sample/presentation corroborates conception and attachment.	Email headers/bodies do not show attachments or file names; proof of attachments depends on Drachmann.	No — emails provide no independent corroboration.
Do the drawings corroborate earlier conception despite later modification date?	File-naming convention (per Drachmann) shows earlier creation predating Nielsen.	No independent evidence of the naming convention or earlier creation; relies on inventor’s statement.	No — drawings uncorroborated and dated later on their face.
Is "unrebutted" evidence sufficient when inventor testimony is uncorroborated?	Apator: lack of rebuttal to their evidence supports priority.	Kamstrup: burden remains on Apator to prove conception; unrebutted self-serving testimony is insufficient.	Court: Apator bears burden; unrebutted, uncorroborated testimony insufficient.

Price v. Symsek, 988 F.2d 1187 (Fed. Cir.) (inventor’s uncorroborated testimony insufficient to establish priority)
Mahurkar v. C.R. Bard, Inc., 79 F.3d 1572 (Fed. Cir.) (conception testimony must be corroborated)
In re NTP, Inc., 654 F.3d 1279 (Fed. Cir.) (rule-of-reason corroboration; inventor cannot self-corroborate)
Perfect Surgical Techniques, Inc. v. Olympus Am., Inc., 841 F.3d 1004 (Fed. Cir.) (elements of swearing behind: conception and diligence)
Brown v. Barbacid, 276 F.3d 1327 (Fed. Cir.) (unwitnessed inventor documents alone do not corroborate conception)
Procter & Gamble Co. v. Teva Pharms. USA, Inc., 566 F.3d 989 (Fed. Cir.) (unwitnessed lab notebooks without corroboration are insufficient)
Singh v. Brake, 222 F.3d 1362 (Fed. Cir.) (unwitnessed notes may have corroborative value under rule of reason but not alone)
Hybritech Inc. v. Monoclonal Antibodies, Inc., 802 F.2d 1367 (Fed. Cir.) (notebook entries can corroborate when supported by other evidence)
In re Magnum Oil Tools Int’l, Ltd., 829 F.3d 1364 (Fed. Cir.) (burden on patentee to prove earlier priority)