What is the iron lung and how does it work?

 

The iron lung, also known as a negative pressure ventilator, is a medical device used to assist individuals with breathing when they are unable to do so on their own, typically due to paralysis of the muscles involved in respiration. It was developed in the early 20th century and was commonly used during the polio epidemics of the mid-20th century.

Here's how the iron lung works:

1. Enclosure: The iron lung is a large, airtight chamber that surrounds the patient's body from the neck down. The patient lies horizontally inside the chamber, with their head protruding from one end.

2. Vacuum and Pressure: The iron lung creates changes in air pressure within the chamber to assist with breathing. When the pressure inside the chamber decreases (negative pressure), the patient's chest expands, causing air to flow into their lungs. Conversely, when the pressure inside the chamber increases (positive pressure), the patient's chest contracts, causing air to flow out of their lungs.

3. Cycle: The iron lung operates in a cyclical manner, alternating between negative and positive pressure to simulate the natural process of breathing. This cycle is typically controlled by a motorized pump or a manual mechanism.

4. Seal: To maintain an airtight seal and prevent air from leaking in or out of the chamber, the patient's neck is usually sealed with a rubber gasket or collar.

The iron lung enabled individuals with polio-related paralysis of the respiratory muscles to breathe effectively by mechanically assisting their breathing. While it was a life-saving device during the polio epidemics, advancements in medical technology, particularly the development of positive pressure ventilators and improvements in respiratory care, have largely replaced the use of iron lungs in modern medicine. However, they remain an important part of medical history and a symbol of the efforts to combat polio and other respiratory diseases.