Rune Elmquist is not a household name. He was one of many Swedish inventors who had gifted the world with such wondrous creations like the zipper (Gideon Sundback, 1917), the three-point seatbelt (Nils Bohlin, 1959), the carton tetra-pak (Erik Wallenberg and Ruben Rausing, 1946), and even the adjustable monkey wrench (Johann Petter Johansson, 1891). Sweden’s most famous innovator, Alfred Nobel, the inventor of dynamite, bequeathed his fortune for the planet’s most prestigious prize that bears his name. Elmquist’s contributions are no less impressive and are widely used devices today: the cardiac pacemaker and the inkjet printer.

Elmquist was born in 1906 and was a prodigious tinkerer. His son Hakan recounted a story about his dad’s high school days. It was the time when radio was the new fad. One morning, Elmquist’s physics teacher came to visit him at his house to listen to a radio for the first time. Sitting on the kitchen table was the electronic gizmo pieced together by the teenage Elmquist.

It was not surprising that the young inventor wanted to pursue a career in engineering. Unfortunately, in the southern city of Lund where he lived, there were no engineering schools. He entered the medical school instead. But that did not stop him from inventing. Elmquist recalled in an interview with Siemens in 1978 that during his first course in internal medicine in 1929, he thought that the method of learning heart sounds was too inefficient. Medical students had to crowd around a patient as they tried to listen to the heart. Elmquist came up with a solution: a device with a microphone that relayed the sounds to individual headphones. That way, they would all hear the same sounds as the professor examined the patient. In 1931, his article on ‘a cheap electric stethoscope for the lecture hall’ appeared in the German medical journal Klinische Wochenschrift.

One of his medical professors was so impressed that he asked Elmquist to improve the electrocardiograph (ECG), a device used to record heart rhythms. The machines at the time were huge, cumbersome, complicated, and very expensive. Elmquist designed a new version that was portable and more efficient.

He eventually completed his medical studies and earned his degree, but he never really practiced medicine. According to his son Hakan, his entire medical career lasted about half a year as a ship’s doctor on a 60-passenger cruise ship. It was the same ship where Elmquist and his wife celebrated their honeymoon.

In the 1950s, his collaboration with the pioneer cardiac surgeon Dr. Ake Senning began. Elmquist was now the head of the medical electronics lab at Elema-Schonander. The company was developing early medical devices for the Karolinska hospital in Stockholm. Senning, in particular, was working on defibrillators, a heart-lung machine, and pacemakers as tools for the rapidly growing field of open-heart surgery. Senning and Elmquist made medical history in 1958 when they implanted the first self-contained pacemaker into a dying 42-year old man. Elmquist fashioned the life-saving device using two silicon transistors, a pair of nickel cadmium batteries, and a pulse generator – all encased in a clear epoxy resin. It was exactly the size of a Kiwi shoe polish tin. That’s because he actually used a Kiwi shoe polish tin as a mold. I asked his son Hakan how his father came up with this idea. Hakan has no clue; ‘Who knows? It was probably just lying around,’ he wrote in an email.

While Elmquist’s role in the pacemaker story is better known, he admitted in later interviews that he considered the technology as a mere engineering curiosity that probably wouldn’t amount to much. As the news about the implantable pacemaker began to spread, Hakan recalled that his father began to receive calls at their house from doctors all over the world, asking for the device. When the younger Elmquist asked if the pacemaker would be a big thing, his father replied that it never would be; it was simply a service for their ECG customers.

What Elmquist was most proud of was his work on the ECG machine. His early versions, while an improvement over the existing devices, still had an annoying feature: they used photographic paper that needed to be developed. Elmquist realized that for an ECG machine to be useful clinically, it should provide instant results. That was how the search for a direct method of printing began.

Creating this new device proved to be the most complicated and technically challenging endeavor for Elmquist. It took many years and a lot of money to develop the tools and technology. There were many setbacks, but Hakan is convinced that his father considered the work on direct-registration printing as the most rewarding.

Elmquist had a knack for finding solutions from unlikely places. In a presentation about his father, Hakan revealed that the inspiration for the ink-jet idea came to Elmquist one cold winter night in Sweden. The inventor was relieving himself in the snow and realized that a thin jet of ink ejected onto rolling paper could produce the ECG tracings.

The idea was simple enough: throw ink on a rolling paper using a small nozzle and high pressure. In the 1978 interview, Elmquist said that in order to create a clinically useful tracing, the jet had to be 10/1000 of a millimeter in diameter. In the early 1940s, with scarce materials due to the war, this was not an easy puzzle to solve. But solve it he did, and on September 21, 1949, the U.S. patent office received the application for ‘MEASURING INSTRUMENT OF THE RECORDING TYPE.’ Patent number 2,566,443 was granted on September 4, 1951.

And so the direct-printing ECG machine using ink-jet technology was born. Elmquist later said that he took his work seriously, but not himself. True to his mantra, he was known to be relaxed and playful. When it came to naming his prized ECG machine, he chose ‘Mingograph,’ which Hakan pointed out was derived from Latin mingo: to pee; a clear tribute to that frigid Scandinavian evening when he needed to micturate in the snow.