First Fully Implantable Pacemaker
Wilson Greatbatch was working on an oscillator for recording tachycardias when he inadvertently connected a 1 MΩ resistor instead of a 10 KΩ resistor. He realized that the lower electrical current could power the implantable pacemaker he was designing. The generator used Mallory mercuric oxide-zinc cells that drove a two transistor, transformer coupled blocking oscillator circuit, which was encapsulated in epoxy resin and coupled to electrodes placed in the myocardium.
In 1958, Greatbatch asked surgeon William Chardack to help him implant the device at the animal lab. When the animal’s heart started beating in rhythm with the device, Dr. Chardack reportedly exclaimed, “Well, I’ll be damned.” The Chardack-Greatbatch pacemaker, the first completely implantable pulse generator, is considered the precursor to a generation of pacing devices powered by mercury batteries. It was first successfully implanted in a human patient in 1960.
Both Greatbatch and Chardack later invented other pioneering devices. In the 1970s, Greatbatch introduced the lithium-iodide battery, which greatly extended the longevity of pacemakers and is now a standard cell for pacemakers. He holds more than 325 patents and is a member of the National Inventors Hall of Fame. Dr. Chardack subsequently developed highly reliable myocardial and endocardial leads using a coiled-spring design, and other innovative devices.