There are about 3 million people in the world with pacemakers with 600,000 pacemakers implanted each year. It has been instrumental in significantly reducing the mortality rates in patients with cardiac rhythm disorders.
The implantable pacemaker was invented by Wilson Greatbatch, an electrical engineer, who also taught at the University of Buffalo. However, this important scientific invention was made completely by accident. Greatbatch was working on an oscillator to record heart sounds in the late 1950s, when he accidentally installed the wrong resistor and the device started giving off a rhythmic electrical pulse.
He describes the events as follows: “It was no accident, the Lord was working through me… The oscillator required a 10 KΩ resistor at the transistor base. I reached into my resistor box for one, but I misread the color coding and got a 1 MΩ resistor by mistake.” When he connected the resistor, the circuit started to “squeg” with a 1.8 millisecond pulse followed by a 1 second interval during which the transistor was cut off and drew practically no current. “I stared at the thing in disbelief,” he said. Wilson Greatbatch immediately realized that this small device could drive a human heart. To put this in context, cardiac pacemakers before Greatbatch’s invention were the size of a television set.
Source: Images Paediatr Cardiol. 2006 Apr-Jun; 8(2):17-81.