Exterior of nVision Medical at 1192 Cherry street in San Bruno, CA. Photo: Jason Doiy/ALM

For Surbhi Sarna, business is personal. At age 13 she developed an ovarian cyst, but at the time the only way to determine if was cancerous was by invasive surgery that risked spreading any cancer.

The cyst ultimately was benign, but it shaped Sarna's career. "Right away, after that experience," she told a UC alumni publication, "I knew that I wanted to be an entrepreneur and start a company dedicated to women's health to try to find an early detection mechanism for ovarian cancer."

As a product development engineer at San Carlos heart health company BioCardia Inc., she worked nights and weekends patenting innovative diagnostic tools for fallopian tubes. She left BioCardia after four years, in 2012, and started her own company, nVision Medical Corp.

The departure appears to have been amicable. "Hey Surbs," BioCardia Vice President for Regulatory Andrew Mackenzie emailed her after reconnecting at a 2013 medical conference. Mackenzie told her it made him "happy to see how successful you have been at pursuing the birth of your company."

Sarna and nVision have indeed grown successful. By 2015, Forbes named Sarna a Tech Superwoman. Then Boston Scientific Corp. paid $150 million plus milestone payments to acquire nVision in 2018. And now, the feelings at BioCardia, a publicly traded company with a market cap of $30 million, seem less warm.

BioCardia and Boston Scientific have been locked in litigation since last year. At a nearly two-hour Zoom hearing before U.S. District Judge Vince Chhabria of the Northern District of California on Thursday, BioCardia argued that Sarna quietly incorporated nVision and began applying for patents just a year into her tenure at BioCardia. "It is very, very common in the valley for people to start up companies while they're still leaving. It's not common that they start the company for two and a half years and never tell anyone," Ian Feinberg of Burlingame's Feinberg Day Kramer Alberti Lim Tonkovich & Belloli argued for BioCardia.

Feinberg accused Sarna of using BioCardia trade secrets to develop her technology for guiding catheters through fallopian tubes. He further sought to impose a constructive trust on the venture capitalists who he said should have seen red flags around nVision's intellectual property and were unjustly enriched by the Boston Scientific acquisition. "They've taken the risk that it will turn out that nVision has contaminated IP," Feinberg said.

That part of the case sounded like a long shot following Thursday's hearing. "At that point is there wrongdoing?" Chhabria asked Feinberg. "You're saying, 'We're going to invest in a company, and there's risk that there may be problems with its IP.' I mean, I assume that happens every day in Silicon Valley."

Sarna agreed by contract to assign all her inventions to BioCardia while in its employ. But the agreement had a carve-out for California Labor Code Section 2870, which specifies that an invention developed on an employee's own time, on subject matter outside the scope of employment, belongs to the employee.

Boston Scientific, nVision and Sarna argue that Sarna's technology has nothing to do with heart health, and that she was always upfront about her plans and ambitions. On the day she interviewed for her job, she told BioCardia she expected to be running a women's health company in five years, Sarna's attorney, Bob Freitas, told Chhabria on Thursday. "That she was doing something in secret" is not true, said Freitas, of Redwood City's Freitas & Weinberg.

Freitas said there are "a whole host of facts" that will show BioCardia knew about Sarna's patents for years and never complained until the Boston Scientific acquisition, long after the statutes of limitations ran. In court papers, nVision notes that BioCardia vice president Mackenzie was at the June 2013 conference where Sarna presented about her company and its technology. "Several patents pending on unique catheter characteristics and methods of use," states a slide deck that accompanied Sarna's presentation that day.

Feinberg acknowledged Thursday that "there is going to be a major fight in this case over statute of limitations, and when BioCardia knew or should have known" about the patents. "That is going to be a real fight."

Faegre Drinker Biddle & Reath partner Timothy Grimsrud appeared briefly for Boston Scientific. He noted that the company announced earlier this year that it's stopped investing in the nVision technology. "This is not a case where there's going to be a product coming out from nVision," he said.

Chhabria sounded open to the argument that Sarna misappropriated BioCardia trade secrets, though he emphasized he was only "thinking out loud" at an early stage of the litigation. On three different occasions he characterized Sarna as having "repurposed" BioCardia technology, even though Feinberg cautioned that he wouldn't put it quite that strongly.

The statute of limitations may be BioCardia's biggest problem, but it will have to wait until summary judgment motions. "If you made me bet," Chhabria said, "I would say it's a summary judgment fight that the defendants are going to have a very good chance of winning."

In the meantime he asked for letter briefs on the venture capital issue and whether nVision was properly added as a defendant. He scheduled another hearing for next week.

"This is a very interesting case. It's a very complicated problem," Chhabria said. "And I want to spend more time, probably a lot more time talking about it."