During the winter of 1957-58, Earl E. Bakken developed the first wearable transistorized pacemaker, the request of heart surgeon, Dr. C. Walton Lillehei. As earlier pacemakers were AC-powered, this battery-powered device liberated patients from their power-cord tethers. The wearable pacemaker was a significant step in the evolution to fully-implantable units.
A key milestone in development of the quartz electronic wristwatch in Switzerland was the creation in 1962 of the Centre Electronique Horloger of Neuchâtel. The Centre produced the first prototypes incorporating dedicated integrated circuits that set new timekeeping performance records at the International Chronometric Competition held at this observatory in 1967. Since then quartz watches, with hundreds of millions of units produced, became an extremely successful electronic system.