Under Armour is developing a new shoe that is said to measure the user's blood pressure. The company has filed a patent application with the U.S. Patent and Trademark Office on June 25 for two possible models of the sneaker. In the first version, the shoe would link to a wearable device and the sole of the shoe would adjust the fit for optimal blood flow to the athlete's leg. The second version would read the user's blood pressure with a detector at the bottom of the shoe. A patent application can indicate what a company is working on but does not guarantee that a product will make it to market.