Iron lungs were used in the past for victims of polio, a virus that paralyses muscles, including the diaphragm needed for breathing. Many polio patients used the machines only during the acute phase of the disease; the muscle action would later slowly return. Some would go on to use the machine only at night, others had to use it permanently. The first time an iron lung was used was on October 12, 1928 at Children's Hospital, Boston.
The use of iron lungs has almost completely ceased. Today, patients with paralysis of the breathing muscles use mechanical ventilators that push air into the airway with positive pressure.