Professor Sullivan is recognised as an international leader in the field of sleep disordered breathing. His major research achievements include characterising the basic physiology of breathing during sleep and the recognition that arousal responses from sleep are crucial to survival in respiratory failure. He has been the key person in Australia promoting the investigation of sleep disorders medicine and he established the first diagnostic sleep laboratories for adults and children. He is known internationally for developing nasal continuous positive airway pressure to treat obstructive sleep apnea. This is now the most widely used treatment for this disease throughout the world.