United States Surgical Corporation (“U.S. Surgical”) appeals from the decision of the United States District Court for the Central District of California granting judgment of willful infringement of U.S. Patent 5,385,553 in favor of Applied Medical Resources Corporation (“Applied”), and awarding damages, enhanced damages, attorney fees, and prejudgment interest totaling $64.5 million. Applied Med. Res. Corp. v. U.S. Surgical Corp., Civ. No. 99-CV-625 (C.D. Cal. Jan. 27, 2005). Because the district court did not err in not applying collateral estoppel to the reasonable royalty rate, substantial evidence supports the jury’s verdict of willful infringement, and the court did not abuse its discretion in admitting evidence regarding a prior litigation, we affirm.