A sharply split federal appeals court reversed course and reinstated a $29.4 million win for Marine Polymer Technologies in its wound dressing patent spat with HemCon Medical Technologies.

The U.S. Court of Appeals for the Federal Circuit, in an en banc decision joined in full by 5 of 9 judges on the panel, ruled that the "intervening rights" of a company accused of patent infringement are only valid when patent claim language is changed during re-examination.