Apple Hit With $184M Interest Charge in Masimo Watch Patent Dispute

A federal judge has ordered Apple to pay an additional $184M in prejudgment interest to medical technology company Masimo. The penalty increases Apple's total liability in the pulse-oximetry patent dispute to approximately $818M, excluding ongoing post-judgment interest. Judge James Selna rejected Apple's argument against the interest, ruling that the payments make the patent owner whole for deprived royalties. The court denied Masimo's request for a 7% interest rate calculation and instead compounded the interest annually at Masimo's own borrowing rate. The original November 2025 jury verdict found that historical Apple Watch heart-rate notifications infringed on Masimo's patent, which officially expired in June 2022. "interest from the time that the royalty payments would have been received merely serves to make the patent owner whole." — Judge James Selna