U.S. patent reveals Apple Watch blood pressure sensor

The U.S. Patent and Trademark Office on Thursday published an Apple patent application that shows the company is working on blood pressure measurement devices including one with a liquid filled sensor.Jack Purcher for Patently Apple:Apple’s invention is directed to a blood pressure measurement device that includes a strap configured to couple the blood pressure measurement device to a user, an air pump coupled to the strap and having a housing defining a surface facing the user, and an inf