St. Jude, Volcano back in court over patent squabble

Three days after fending off a patent suit from St. Jude Medical ($STJ), Volcano ($VOLC) is taking the device giant back to court in a countersuit.

St. Jude filed the first action, suing Volcano in 2010 on claims that the company violated its patents related to heart diagnostic tools. On Friday, a federal jury found against St. Jude, and now the two parties will endure a second jury trial to determine whether St. Jude infringed on three Volcano patents, Bloomberg reports.

In their opening statements, Volcano's attorney asserted that the company invented the technology used in arterial diagnostic devices, while St. Jude's lawyer claimed his client is "a true innovator" that revolutionized heart devices on its own merits, according to Bloomberg. The trial is scheduled at least through this week.

After Friday's ruling, Volcano's shares jumped about 12%, peaking at $29.88 on Monday morning before evening out at around $28.50 by 11 a.m. ET. St. Jude is expected to appeal the earlier dismissal as it battles the countersuit.

- read the Bloomberg story