Accidental Discoveries · Medicine
The Wrong Resistor That Grabbed a Heartbeat Out of Thin Air
In 1956, an engineer in Buffalo, New York reached into a box of resistors, pulled out the wrong one, and soldered it into his circuit. The box hummed to life: a short tick, a one-second pause, a tick again. He knew that rhythm. It was a heartbeat. "I stared at the thing in disbelief," Wilson Greatbatch said later. He had been trying to build a device that *listened* to hearts. He had accidentally built one that could run them.
· 5 min read · Filed under Medicine

What happened?
Wilson Greatbatch was not, by his own account, a prodigy. He was a Navy radioman in the Second World War, then a telephone repairman, then a Cornell engineering student on the G.I. Bill who tested poorly and worked too many jobs. One of those jobs was wiring instruments to sheep and goats at Cornell’s animal behavior farm — attaching sensors that tracked blood pressure, heart rate, and brain waves.
It was there, over brown-bag lunches in 1951, that two visiting surgeons described a condition called heart block: the electrical signal that normally travels from the heart’s upper chambers to its lower chambers fails to arrive. The ventricles beat too slowly, or fall out of sync, and the patient faints, gasps, or dies. To Greatbatch, a radio man, it sounded like a familiar problem in unfamiliar clothing. The signal wasn’t getting through. “When they described it, I knew I could fix it,” he recalled.
He filed that away for five years. By 1956 he was back in Buffalo, teaching electrical engineering at the University of Buffalo and moonlighting at the Chronic Disease Research Institute, where he was building a marker oscillator — a small circuit meant to help record fast heart sounds. The circuit needed a 10,000-ohm resistor. A resistor is just a component that throttles the flow of electric current; the amount it throttles is measured in ohms, and the value is painted on the body in colored stripes. Greatbatch reached into the box and came out with one striped almost identically — but rated at one megohm, a hundred times the resistance he wanted.
He soldered it in. Instead of doing what a marker oscillator does, the circuit fired a pulse lasting 1.8 milliseconds, went quiet for a full second, then fired again. Lub. Dub. Lub. Dub.
Three weeks after showing the idea to William Chardack, chief of surgery at Buffalo’s Veterans Administration Hospital, Greatbatch arrived with a hand-built device roughly two cubic inches in size, running on two Texas Instruments transistors. On May 7, 1958, Chardack and fellow surgeon Andrew Gage exposed a dog’s heart and Greatbatch touched two wires to it. The device took over the heartbeat. Everyone in the room stared.
Then reality arrived. The team had sealed the electronics in electrical tape, which turned out to be a poor defense against the inside of a living body; fluid seeped in and shorted the circuit after about four hours. They switched to casting the whole unit in a solid block of epoxy. Greatbatch quit his jobs, moved into an unheated barn behind his house warmed by a wood stove, and built fifty pacemakers by hand on