Ventilators provide respiratory assistance to patients who cannot breathe on their own or who require assistance to maintain adequate ventilation because of illness, trauma, congenital disorder, or drugs (e.g., anesthetics).

Ventilators consist of several components, which include a flexible breathing circuit, a control system, monitors, and alarms. The ventilator delivers breathable gas using a double-limb breathing circuit. The gas may be heated or humidified...