A federal judge sided with St. Jude Medical (NYSE:STJ) in a patent infringement dispute with Access Closure Inc. over technologies used to close holes in arteries.

Last year a jury in the U.S. District Court for Western Arkansas found that Access violated an STJ patent, but also found the patent invalid because of its close similarity to another piece of St. Jude’s intellectual property, according to court documents.

St. Jude argued that federal safe harbor rules apply to the two patents. Those rules protect patents that arise for patent applications that cover more than one invention. The U.S. Patent & Trademark Office can force those applications to be split so that each patent covers only one invention. In those cases, the split patent is given “safe harbor” from charges of double-patenting.

Sign up to get our free newsletters delivered straight to your inbox

Judge Harry Barnes decided yesterday that, despite the patent’s invalidity, it’s protected by the safe harbor provisions from Access Closure’s accusation of double-patenting because it arose from just such a USPTO ruling.

“Both of these patents trace their lineage to a patent in which a restriction requirement was imposed. Thus, both of these patents were filed as a result of a restriction requirement,” Barnes wrote, according to court documents.