LOUISVILLE, Kentucky (AP) ― It may sound far-fetched, but scientists are attempting to build a human heart with a 3-D printer.

Ultimately, the goal is to create a new heart for a patient with their own cells that could be transplanted. It is an ambitious project to first, make a heart and then get it to work in a patient, and it could be years ― perhaps decades ― before a 3-D printed heart would ever be put in a person.

The technology, though, is not all that futuristic: Researchers have already used 3-D printers to make splints, valves and even a human ear.

So far, the University of Louisville team has printed human heart valves and small veins with cells, and they can construct some other parts with other methods, said Stuart Williams, a cell biologist leading the project. They have also successfully tested the tiny blood vessels in mice and other small animals, he said.

Williams believes they can print parts and assemble an entire heart in three to five years.

The finished product would be called the “bioficial heart” ― a blend of natural and artificial.

The biggest challenge is to get the cells to work together as they do in a normal heart, said Williams, who heads the project at the Cardiovascular Innovation Institute, a partnership between the university and Jewish Hospital in Louisville.

An organ built from a patient’s cells could solve the rejection problem some patients have with donor organs or an artificial heart, and it could eliminate the need for anti-rejection drugs, Williams said.

If everything goes according to plan, Williams said the heart might be tested in humans in less than a decade. The first patients would most likely be those with failing hearts who are not candidates for artificial hearts, including children whose chests are too small to for an artificial heart.

Hospitals in Louisville have a history of artificial heart achievements. The second successful U.S. surgery of an artificial heart, the Jarvik 7, was implanted in Louisville in the mid-1980s. Doctors from the University of Louisville implanted the first self-contained artificial heart, the AbioCor, in 2001. That patient, Robert L. Tools, lived for 151 days with the titanium and plastic pump.

Williams said the heart he envisions would be built from cells taken from the patient’s fat.