Passing a wire through a diseased heart valve is a bit like threading a wet noodle into a garden hose while the tap water is flowing.

Passing a wire across a heavily calcified heart valve is the first step in many modern procedures to repair or replace it. But threading it through the jet of blood streaming out of the patient's narrowed valve can be a major technical challenge, especially since knocking bits of built-up calcium can trigger serious health problems.

Doctors at Mayo Clinic recently had an idea: What if they could aim the wire at the valve using a special catheter with a small funnel on the end to capture the blood flow and center the gadget right above the jet? That idea will be put to use in a human clinical trial later this year as part of a collaboration between Mayo and Boston Scientific Corp. — a long-running collaboration being publicly unveiled Wednesday morning.

"In the past, we've had companies come down and try to sell us something. They'd want to collaborate, and then try to sell us something. This has been about, how do we make a better product?" said Jim Rogers, a patent lawyer and chairman of Mayo's tech arm, Mayo Clinic Ventures. Boston Scientific was "willing to trust us, and we were willing to trust them, and I think good things have come of that."

The collaboration agreement between one of the state's most storied health care providers and one of Minnesota's largest medical-device companies — Massachusetts-based Boston Scientific has 5,000 employees in the state — was quietly brokered three years ago and allowed to work without any public announcement.

Both sides describe the collaboration as a leap of faith.

"This really starts at the beginning. It's going in with a blank sheet of paper, not us coming in with specific products and ideas," said Kevin Ballinger, a medical-device engineer and senior vice president with Boston Scientific. "It's engineers and physicians in their environment, jointly understanding what are some of the unmet clinical needs, before talking about product solutions."

More than 50 ideas have been run through the collaborative system already, and the centering catheter is one that has made it to the verge of testing in humans. Another one expected to enter clinical trials later this year is a new use for Boston Scientific's existing Precision Spectra Spinal Cord Stimulator.

All told, the Mayo-Boston Scientific collaboration has about a dozen ongoing projects, including four that are expected to reach "first-in-man" clinical trials in 2016. The parties are disclosing only two of the four ideas so far.

Closely guarded secrecy around new ideas has long been the norm in med-tech, as have nasty patent fights. In separate interviews, officials with Mayo Clinic Ventures and Boston Scientific said the key to making sure that their collaborations don't devolve into litigation is the overarching collaboration agreement they signed three years ago.

"We have predetermined how any party will share in any financial benefits that arise from the work that we do together. That creates some level of trust," said Andrew Danielsen, who works in business development at Mayo Clinic Ventures. "But as any good lawyer will tell you, the contract is the last thing you should rely on. I have to say … this has worked well because of good people. They've been good partners."

That has made the agreement less about patent rights and more about setting up a structure so that physicians felt comfortable working closely with Boston Scientific engineers, with the common understanding "that the value that is created here is shared fairly," Danielsen said.

Some things won't change. Boston Scientific will only agree to pursue an idea if it will fit well in the company's long-term product pipeline. Mayo will continue nurturing some ideas in-house, or figure out how to fund them elsewhere. And Mayo says it is not changing its rules on managing physician conflicts of interest or providing informed consent to patients getting experimental treatments.

One big change took place in December, though, when President Obama signed a law suspending for two years the 2.3 percent excise tax on medical-device sales that had been imposed by the Affordable Care Act. Executives at Boston Scientific said the decision caused the company to double its spending on the Mayo collaboration to a level in the multimillion-dollar range, Rogers said.

"To see Boston Scientific basically now having the money coming from the device tax repeal, and they want to reinvest in our collaboration — to us, that says a lot about where their leadership is on the importance of this collaboration," Rogers said. "And I know we feel the same way on our side."