A federal appeals court today upheld a patent board’s decision to invalidate some claims in a surgical stapler patent owned by Johnson & Johnson (NYSE:JNJ) subsidiary Ethicon, following a challenge lodged by Medtronic (NYSE:MDT) subsidiary Covidien.

Covidien asked the U.S. Patent & Trademark Office for an inter partes review of 14 claims in patent 8,317,070, covering “Surgical stapling devices that produce formed staples having different lengths,” in March 2013.

The Patent Trial & Appeals Board found in August of that year that the contested claims would have been obvious over prior art, issuing a final decision in June 2014. Ethicon appealed to the U.S. Court of Appeals for the Federal Circuit, arguing that the board’s final decision is invalid because the same panel made the both the decision to review and the final decision, and made a mistake in ruling the claims obvious.

The the appeals court today upheld the PTAB’s decision invalidating the claims, finding that “neither the statute nor the Constitution precludes the same panel of the board that made the decision to institute inter partes review from making the final determination. We also find no error in the board’s determination that the ‘070 patent claims would have been obvious over the prior art,” according to court documents.