Naturally, all eyes will be fixated on the athletes at this year's U.S. Open, but some will notice the skin-tight nylon tees on the backs of the event's ball boys, representing Ralph Lauren's first foray into the emerging world of wearable technology. Woven directly into the fibers of the sleek black top is conductive silver-coated thread and an array of sensors, which allows for the monitoring of heart rate, breathing and stress levels. The Polo Tech shirt, made in collaboration with Canadian tech firm OMsignal, is equipped with a Bluetooth-enabled and detachable black box that sends the pertinent data to an iOS app. Consequently, by gathering a baseline for your activity and biometrics, the app can develop a "Fuel" gauge, which measures how much fuel you expend in a given day. Ralph Lauren will outfit ball boys with the Polo Tech Shirt during select matches at the U.S. Open, with plans to expand its wearable tech offerings in the coming months.