U.S. Patent No. 8,893,559. Directed to ultrasound meter.

Patentee attempted to swear behind prior by 18 days (page 2).  Emails, all from the inventor, were dated before the prior art filing date (pages 2-3).  The “attached” files in the emails were not attached, so the mere statement of having a “new thing” in the email is not corroborated (page 5).  The inventors statement of earlier creation of drawings shown as having been modified after the prior art filing date relies just on the inventor (page 6).  All the evidence relies on the inventor to show conception, so there is no corroboration (pages 6-8).

Hindsight: Save conception documentation with the attached files.  Have a witness sign notes or otherwise indicate review and understanding of conception.  Of course, this case relies on pre-AIA so it may be too late for this advice.  Still, post AIA 102 allows for derivation, so documenting any disclosure (when and to whom) may be important.