Medtronic, the world's largest medical-device maker, is using microelectronics and chip manufacturing to shrink pacemakers. Whereas current pacemakers are about as big as a silver dollar, Medtronic's device would be smaller than a Tic Tac. At that size, the device would be small enough to be inserted via catheter, rather than invasive surgery. The device is still a research instrument, says Stephen Oesterle, Medtronic's senior vice president for medicine and technology, but it could be on the market in five years. So far, Medtronic has developed most of the components--a circuit board, an oscillator to generate current, a capacitor to store and rapidly dispense charge, memory to store data, and a telemetry system to wirelessly transfer that data.