Newswise — Saving a life can be easy. Indeed, few people realize how easy it has become for the average person to intervene constructively in a cardiac emergency, where every second counts. Automated external defibrillators, or AEDs, are being installed with growing frequency in public spaces such as offices, airports, and shopping centers, enabling bystanders with virtually no medical expertise to become first responders.

An AED is designed to deliver an electric shock to restart a heart that has gone into cardiac arrest. Making it simple to use, however, required a sequence of crucial medical, legal, and engineering breakthroughs. Mark Kroll, Karl Kroll, and Byron Gilman, the co-founders of Survivalink, a company that made the first single-button AED, describe the developments that enabled the medical device to emerge from the hospital and begin to become as common as the ordinary fire extinguisher.