NEW YORK (AP) — Medical products company Covidien Plc. said Thursday it is suing a unit of Johnson & Johnson, claiming patent infringement from a line of ultrasonic surgical products. Covidien claims that Ethicon’s Harmonic line of ultrasonic surgical products infringes several Covidien patents. Covidien wants J&J’s Ethicon unit to stop making the products and pay damages to Covidien. The lawsuit was filed in U.S. District Court for the District of Connecticut. Covidien said some of the same Ethicon devices were found to infringe the same patents in a previous case, though that was dismissed on an appeal. The court did permit the filing of the new case. “We firmly stand behind our products and intellectual property, which allow us to advance patient care by bringing innovative medical devices to the market,” Ethicon said in a statement.