He Reached Into the Wrong Bin, Soldered in the Wrong Resistor, and Built the First Implantable Pacemaker

US3057356 was filed by Wilson Greatbatch on July 22, 1960, under the title Medical Cardiac Pacemaker. It describes a device small enough and sealed well enough to be placed inside a human body and left there, and it exists because of a mistake at a workbench.

What he was actually building

Greatbatch was an electrical engineer in Buffalo, New York, working in the late 1950s on an oscillator circuit intended to record heart sounds. Recording, not stimulating.

He reached for a resistor to complete the circuit. The value he needed and the value he picked up were different, and accounts of the specific figures vary in the retelling, so the detail that matters is the effect rather than the numbers. With the wrong resistor in place, the circuit stopped behaving like a recorder and began putting out a regular electrical pulse: a short pulse, then a pause, then another.

He listened to the rhythm and recognized it. It sounded like a heartbeat.

Why he was ready for it

This is the part of the story that gets skipped, and it is the reason the accident amounted to anything.

Years earlier, while working on a different project, Greatbatch had sat at lunch with two surgeons who described a condition called complete heart block, in which the electrical signal that tells the heart's ventricles to contract fails to arrive from the atria. The heart has functioning muscle. The wiring has failed. Patients died from a signaling fault in an organ that was otherwise capable of working.

He had carried that around for years. So when a circuit on his bench began emitting a steady pulse, he was not looking at an anomaly. He was looking at the missing signal for a problem he had been told about and had never stopped thinking about.

Nothing about the accident was useful on its own. Somebody else with that resistor gets a broken recorder.

The problem that was harder than the circuit

Pacing a heart electrically was not new in 1960. External pacemakers existed. They were large, they ran on mains power or bulky batteries, and the patient was tethered to the machine by wires passing through the skin, which is both immobilizing and a standing infection risk.

The circuit Greatbatch had was small and drew very little power. The real engineering problem was keeping the body and the electronics apart.

The human interior is warm, salty, wet, and chemically aggressive. It will destroy unprotected electronics, and leaking components will injure the patient. Greatbatch worked on sealing the device, eventually using epoxy and later moving to hermetic metal enclosures, so that the unit could sit inside a person and simply continue working.

The first implant in a human came in 1960, in a patient at the Veterans Administration hospital in Buffalo, in work with the surgeon William Chardack. The device was tested in dogs first.

The battery, which he also solved

Early implantable pacemakers ran on mercury batteries with short and unpredictable lives, which meant surgery to replace a unit every couple of years. That is a serious cost in an implanted device.

Greatbatch went after this problem too, and adapted the lithium iodide battery for implantable use. It extended pacemaker life dramatically, to a decade or more, and it became the standard. This is arguably as important as the pacemaker circuit itself, and it is far less well known.

He founded a company to manufacture the batteries and held more than 300 patents. He received the National Medal of Technology in 1990 and was inducted into the National Inventors Hall of Fame in 1988.

Millions of people are alive with one of these in their chest. The circuit that started it was an oscillator that had been built wrong, noticed by the one person who already knew what the right kind of wrong sounded like.

See the original

The full text and figures of US3057356 are on patents.us.