Back in the 1950s, hospital-equipment repairman Earl Bakken wasn't afraid of the sight of blood. He had a locker next to the surgeons, and he would often keep the doctors' equipment running during procedures or design devices to order.

At the same time, war veteran and University of Minnesota surgeon Dr. Walt Lillehei wasn't afraid to risk patients' lives to pioneer new ways to fix broken hearts. Lillehei's supervisor, surgery chief Dr. Owen Wangensteen, encouraged doctors to try ideas that many in the medical establishment saw as too risky.

Some of the things they did could never happen today, like Lillehei's decision to use the world's first portable battery-powered pacemaker on a patient just four weeks after Bakken custom-designed it in his northeast Minneapolis garage in 1957.

Yet on July 1, the Smithsonian's National Museum of American History will shine a flattering spotlight on medical innovation and risk-taking in 1950s Minneapolis in a new exhibit called "Places of Invention."

"We are trying to get at these good story nuggets, that have a strong sense of place, of critical mass of people and resources and ideas, that had this sort of moment of fluorescence," said Monica M. Smith, project director for the exhibit in the American history museum's newly renovated west wing.

Bakken went on to found Medtronic, which spun off dozens of other med-tech companies on its way to becoming the world's largest medical-device company today. Several early Medtronic pacemakers will be on display in the national history museum, whose holdings from inventors include a Thomas Edison lightbulb and an Alexander Graham Bell telephone.

"It's an exciting testimony to that time in Minnesota. But I think even more importantly, it is hoped that it would be an encouragement to young minds," said Dr. Craig Lillehei, a pediatric transplant surgeon in Boston and son of Walt Lillehei, who died in 1999. "Obviously we're Minnesotans and we are proud of our state, but it is bigger than that."

Synergy in technology

The state's "Medical Alley" med-tech sector bloomed from those early collaborations at the U in the 1950s, which in turn benefitted from the presence of big technology companies such as Control Data. Minnesota will be one of six technology hot-spots featured in the 3,330-square-foot exhibit in Washington, curated by the history museum's Lemelson Center for the Study of Invention and Innovation.

Others include Silicon Valley of the 1970s and '80s, birthplace of early personal computers, and Hartford, Conn., in the late 1800s, where early techniques in precision manufacturing were pioneered. Modern-day Fort Collins, Colo., is included for its focus on sustainable energy technology.

"Places of Invention" is among the offerings that will be unveiled when the Smithsonian reopens its renovated first-floor west wing on July 1, and it will remain on display through 2020. It's supported financially by the National Science Foundation.

Sketches of the exhibit show the Minnesota section labeled "Medical Alley," a term that sprung up later to describe the cluster of medical technology companies that dot the state from Rochester to Duluth, with a dense concentration in and around Minneapolis and St. Paul.

Today the cluster includes more than 500 small and large businesses and more than 36,000 employees. Many in the community today prefer the more expansive term "LifeScience Alley," which is also the name of the state's 20-year-old lobbying group, based in St. Louis Park.

"This is the United States history museum at the Smithsonian, and we are next to Silicon Valley," said Shaye Mandle, CEO of LifeScience Alley. "And it is sort of on us to leverage that and tell the story that continues to exist."

Pioneering in the O.R.

In addition to the Medtronic pacemakers in the exhibit, Smithsonian visitors can see a 1955-vintage device known as a DeWall-Lillehei bubble oxygenator.

The device is significant in the state's medical history because Minnesota in the 1950s and '60s was known as a center for pioneering open-heart surgery. Special devices like bubble oxygenators were needed to keep patients' blood oxygenated while it was diverted outside the heart during an open-heart procedure.

Lilliehei was among early experimenters in using controlled hypothermia during heart surgery, as well as a controversial technique called "cross-circulation," in which an adult's bloodstream could be connected to a child's during surgery so that the adult's heart and lungs oxygenated both people's blood.

"That gave you the chance to have a 200 percent mortality. You could lose both the parent and the child if something went seriously awry," said David Rhees, executive director of the Bakken Museum in Minneapolis. "There was a group of surgeons who objected … [but] Wangensteen said, go ahead and do it. Try it. Because they didn't have a lot of alternatives. Some of these children who were suffering from congenital heart problems, they were doomed to an early death if they didn't get a hole in the heart fixed."

The Smithsonian's Smith thinks Lillehei's willingness to innovate in risky ways was probably influenced by his time in the Army Medical Corps in Europe, trying to save patients on the battlefront during World War II. The University of Minnesota, meanwhile, was well-positioned to take advantage of a post-war surge in technology and research spending because it already had an active research program under Wangensteen's leadership.

Earl Bakken was in the right place at the right time. An Army volunteer and longtime tinkerer, Bakken co-founded Medtronic in 1949 and took on the role of repairing medical devices in Wangensteen's surgery department.

His strong stomach proved to be an asset, just like his ability to quickly engineer solutions.

"The engineers in the hospitals, for one thing, they didn't like the sight of blood," said Rhees, who has interviewed dozens of people about the era for an ongoing history project of his own. "Earl could stand the sight of blood. So that was one of the selling points: He didn't faint during surgery."

Joe Carlson • 612-673-4779

Twitter: @_JoeCarlson