An artificial lung is a medical device designed to take over the function of natural lungs, which is to exchange oxygen and carbon dioxide in the blood. It is often used in patients with severe respiratory failure or during surgeries where lung function needs to be temporarily supported. The device can help maintain adequate oxygen levels in the body while allowing the lungs to heal. These devices can be part of a larger system, such as extracorporeal membrane oxygenation (ECMO), which pumps blood out of the body, oxygenates it, and then returns it. Artificial lungs are crucial in critical care settings, providing life-saving support for patients with conditions like COVID-19 or severe pneumonia.