 In California, Osborn collaborated with cardiac surgeon Frank Gerbode on the development of a heart-lung bypass machine that would allow open-heart surgery.Gerbode and Osborn's first open-heart surgery using CPB (a repair of a ventricular septal defect) was completed in 1956.In 1958, when physicians were still skeptical of open-heart surgery and CPB, Osborn and Gerbode arranged to have a heart surgery televised before a Bay Area audience of 1.2 million people.