Minnesota's doctors and the institutions they built played a distinguished role in the medical revolution of the past 150 years. The Mayo Clinic and the University of Minnesota Medical School pioneered treatment techniques that drew patients and students from around the world. At St. Mary's Hospital in Rochester, Dr. William W. Mayo and his sons, William J. Mayo and Charles H. Mayo, achieved notable success in the new field of surgery during the 1890s, and by 1904 the two doctors were operating on over 3,000 patients each year. New laboratories, improved medical record keeping, advanced training for physicians in many specialties, and quality diagnosis and care in well-equipped modern hospitals followed, giving the Mayo Clinic a worldwide and still growing reputation. In Minneapolis, the University of Minnesota Medical School earned its own national reputation through both cooperation and competition with the Clinic. Dr. Charles N. Hewitt of Red Wing led early efforts against typhoid, smallpox, and other deadly infectious diseases through vaccination and sanitation regulations and was a regular public health lecturer at the University. In the 1930s Dr. Owen H. Wangensteen revolutionized abdominal surgery with the invention of gastric suction procedures. The medical school also pioneered open heart surgery, introduced the heart pacemaker and artificial heart valves, and in recent years played a major role in organ transplantation. These contributions helped create a concentration of fine hospitals and clinics and a sophisticated electronics industry producing pacemakers, valves, and other devices to heal the sick and prolong life.