An iron lung works by creating rhythmic changes in air pressure around the patient's chest, mimicking the natural process of breathing. Essentially, it forces air in and out of the lungs when a person's muscles are unable to do so.
Here's a more detailed explanation:
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Encasing the Body: The patient is placed inside a sealed, airtight metal cylinder (the "iron lung") with only their head protruding.
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Pressure Changes: A bellows, powered either electrically or manually, is connected to the cylinder. This bellows pumps air in and out of the chamber, alternately increasing and decreasing the air pressure within.
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Inspiration (Inhaling): When the air pressure inside the tank is decreased (made negative), the patient's chest expands due to the higher pressure outside the tank acting on the chest. This expansion draws air into the lungs, just like normal inhalation.
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Expiration (Exhaling): When the air pressure inside the tank is increased (made positive or less negative), the chest is compressed. This forces air out of the lungs, simulating exhalation.
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Mimicking Natural Breathing: By rhythmically altering the pressure, the iron lung effectively takes over the function of the diaphragm and other respiratory muscles, forcing the patient to breathe. The rate and depth of breathing can be adjusted by controlling the bellows.
In essence, the iron lung is a non-invasive mechanical ventilator that uses external pressure to facilitate breathing for individuals with paralyzed or weakened respiratory muscles.
