Respiratory Interventions businesses, which are part of the company's Medical Surgical Portfolio. Acquisition history Medtronic Medtronic plc Medtronic Inc. (Founded 1949) Ardian Inc (Acq 2010) Osteotech Inc (Acq 2010) ATS Medical (Acq 2010) Krauth Cardiovascular (Acq 2010) Fogazzi (Acq 2010) Invatec (Acq 2010) PEAK Surgical, Inc< (Acq 2011) Salient Surgical Technologies Inc (Acq 2011) China Kanghui Holdings (Acq 2012) NGC Medical (Acq 2014) Sapiens Steering Brain Stimulation (Acq 2014) TYRX Inc (Acq 2014) Covidien (Formed 2007 from Tyco International healthcare business spin off) Sapheon Inc (Acq 2014) Reverse Medical Corporation (Acq 2014) Given Imaging (Acq 2014) Aspect Medical Systems Somanetics Corp (Acq 2010) ev3 Inc (Acq 2010) CV Ingenuity (Acq 2012) BÂRRX (Acq 2012) Newport Medical Instruments (Acq 2012) superDimension (Acq 2012) Oridion Systems (Acq 2012) VNUS Medical Technologies Advanced Uro-Solutions (Acq 2015) Diabeter (Acq 2015) CardioInsight Technologies (Acq 2015) Aptus Endosystems (Acq 2015) RF Surgical Systems (Acq 2015) Medina Medical (Acq 2015) Lazarus Effect (Acq 2015) Bellco (Acq 2016) HeartWare International Inc (Acq 2016) Crospon (Acq 2017) Mazor Robotics (Acq 2018) Nutrino Health Ltd (Acq 2018) Titan Spine (Acq 2019) Klue (Acq 2019) Stimgenics, LLC (Acq 2020) Medicrea (Acq 2020) Companion Medical (Acq 2020) Avenu Medical (Acq 2020) Intersect ENT (Acq 2022) Digital Surgery (Acq 2020) Affera, Inc. (Acq 2022) Global rankings In May 2018, Medtronic was ranked as the world's largest medical device company by 2017 revenues (see table below). In March 2017, Bloomberg's database of U.S. tax inversions listed Medtronic and Wright Medical Group (Medtronic's 2015 inversion to Ireland was over $100 billion, while Wright's 2015 inversion to the Netherlands was $3.3 billion), as the only U.S. tax inversions of a U.S. medical device company in history. In February 2018, the Wall Street Journal listed Medtronic's 2015 tax inversion to Ireland as the largest U.S. corporate tax inversion executed between 2013 and 2016. In May 2018, Medtronic was ranked as the largest corporate tax inversion in history. Business units and subsidiaries Medtronic has four main business units: the Minimally Invasive Therapies Group, the Diabetes Group, the Restorative Therapies Group, and the Cardiac and Vascular Group. Medtronic develops and manufactures devices and therapies to treat more than 30 chronic diseases, including heart failure, Parkinson disease, urinary incontinence, Down syndrome, obesity, chronic pain, spinal disorders and diabetes. CRDM Cardiac rhythm disease management (CRDM) is the oldest and largest of Medtronic's business units. Its work in heart rhythm therapies dates