A New York University cardiologist claims Apple’s Watch uses his patented heartbeat-monitoring invention and has filed a lawsuit.

Dr. Joseph Wiesel, who teaches at NYU School of Medicine, filed a suit Friday against the tech giant, in federal court in Brooklyn. Wiesel claims the Apple Watch infringes his patent for a method to detect an irregular heartbeat.

Apple watch that can measure the wearer’s heart rate and can provide notifications of an irregular pulse.

Wiesel said his invention covered “pioneering steps” in atrial fibrillation detection by monitoring “irregular pulse rhythms from a succession of time intervals.” He said he first contacted Apple in September 2017, giving the Cupertino, California-based company detailed information about the patent.

Apple has “refused to negotiate in good faith to avoid this lawsuit,” Wiesel contends in the suit. He wants the court to order Apple to pay him royalties and, barring that, to block the company from using his invention without permission.