ATS Medical, Inc. (Nasdaq: ATSI) develops and manufactures products for the cardiac surgery market, focusing on heart valve therapy and surgical cryoablation; its core offerings include mechanical and biological heart valves such as the ATS Open Pivot heart valves for aortic and mitral valve replacement, ATS 3f tissue heart valves, Simulus semi-rigid annuloplasty rings for valve repair, CryoMaze cryoablation systems for treating cardiac arrhythmias, and related surgical tools and accessories including robotic surgery products. Founded in 1991 and headquartered in Minneapolis, Minnesota, the company operates globally across more than 60 countries with subsidiaries in Europe and Asia. In 2010, ATS Medical was acquired by Medtronic, Inc. for approximately $370 million, integrating its technologies into Medtronic's structural heart disease portfolio; earlier, it acquired CryoCath Technologies' surgical cryoablation business in 2007 for $22 million and received FDA approval for the ATS Simulus annuloplasty ring.