Iron Lung: History, Current Use, and Legacy

The iron lung (negative pressure ventilator) is nearly obsolete but still used by a handful of polio survivors.

History

• 1928: Philip Drinker invents "Drinker respirator."
• 1930s–50s: Widespread during polio epidemics; saved thousands.
• 1955: Salk vaccine → polio decline → iron lung obsolescence.

Mechanism

Chamber seals body from neck down; alternating negative/positive pressure mimics pleural pressure changes → passive inspiration/active expiration.

Current Use (2024)

• ~<10 users worldwide (mostly US).
• Conditions: Post-polio syndrome, high cervical SCI, central hypoventilation, neuromuscular diseases (Guillain-Barré, ALS, muscular dystrophy) where positive pressure ventilation fails or is intolerable.
• Modern alternatives: Non-invasive ventilation (BiPAP), tracheostomy + mechanical vent, diaphragm pacing.

Legacy

Symbol of mid-century public health triumph; pioneered mechanical ventilation principles. Preserved in museums (Smithsonian, etc.).