Artificial breathing aids

reasons why someone can't get enough oxygen into their blood stream:
1. alveoli are damaged, surface area for gas exchange is reduced
2. person is paralysed, muscles wont work to pull ribcage up and out
3. if tubes leading to lungs are narrowed, less air can be moved through them
Breathing aids developed:
1. Iron lungs
  1. Used for paralysed. person lay with their chest sealed in a large metal cylinder, when air was drawn out of cylinder, person's chest moved out and they breathed in. The vacuum created inside formed a negative pressure. When air was pumped back into cylinder, it created pressure on chest and forced air out of lungs.
2. Breathing aids which force measured amounts of air into lungs use positive pressure.
  1. Bags of air linked to masks can force air down trachea.
3. Positive pressure aids are often smaller, easier to manage in the home and can be controlled by computers.

Resource summary

	Created by elliesussex almost 11 years ago