5. Abiomed
R&D spend: $50.0 million
Percent of revenues: 15.1%
2017 overall revenue rank: 89
Abiomed (Nasdaq: ABMD) touts its Impella heart pumps as the world’s smallest – with more than 60,000 patients treated so far. The Impella device is meant to help restore blood flow and allow the heart to rest after a heart attack, according to the Danvers, Mass.–based company. Snaked through the femoral or axillary artery, the device spins at 50,000 revolutions per minute as it sits in the heart. It sends blood away from the heart and out to the body.