Masimo Corp. accuses its erstwhile partner, Mindray Medical, of patent infringement and breach of contract. Masimo (NSDQ:MASI) is accusing its onetime partner, Mindray (NYSE:MR), of patent infringement and breach of contract in a lawsuit filed in California last month. The complaint alleges that Mindray broke a more than 10-year-old deal to incorporate Masimo’s pulse oximetry technology into its Beneview device and violated 9 Masimo patents in the process, according to court documents. “Over the last several years, Masimo experienced a significant drop in Mindray Shenzhen’s purchasing of Masimo SET boards. Over this same period, Masimo’s share of the market for pulse oximetry monitors has increased significantly,” according to the lawsuit.