The Federal Circuit Clarifies Who Can Be an Expert In Patent Cases

Expert witnesses play a critical role in patent litigation, where judges and juries without technical training are expected to adjudicate often highly technical issues related to the patented invention, the accused products, and the state of the art in the relevant industry at the time of the invention. But without the right specialized knowledge, training, or experience, a witness may not qualify as an expert and his/her opinions will not be helpful. Many issues in a patent lawsuit — including claim construction, infringement, and validity — require assessing evidence from the perspective of a hypothetical "person of ordinary skill in the art." Thus, to be qualified to offer technical expert testimony in a patent case, "an expert must at a minimum possess ordinary skill in the art." Kyocera Senco Industrial Tools Inc. v. International Trade Commission, 22 F. 4th 1369, 1377 (Fed. Cir. 2022).

In Osseo Imaging, the patent owner Osseo argued at trial that a person of ordinary skill in the art would have, among other qualifications, three to five years of experience in a diagnostic imaging environment that uses the techniques described in Osseo's patents. On cross-examination, the accused infringer sought to disqualify and discredit Osseo's technical expert, Dr. Omid Kia, by showing that, while he met the definition of a person with ordinary skill by the time of trial, he lacked the required diagnostic imaging experience at the time of the invention in 1999. The district court judge rejected the argument, and the jury found in favor of the patent owner. Osseo Imaging, LLC v. Planmeca USA Inc., No. 1:17-cv-01386, 2023 WL 1815975, at *3 (D. Del. Feb. 8, 2023).