Mick Farrell’s father questioned his son’s double degree from MIT when he didn’t immediately see the opportunity facing the sleep apnea company. But the younger Farrell quickly came around and helped build ResMed into a $15 billion company, with the last five years at the helm as CEO. Today, however, Farrell has ResMed beginning to take a very different path, migrating away from pure medical device sales and into selling software and other tech services to physicians.