There are three basic groups that all needs can be placed. These three groups of needs are economic, military, and social. An invention is guaranteed failure if it does not meet one of these needs (Sloan and Northam, "Invention") .
. There were many social needs to be satisfied in the 1920s. Many inventions during the 1920s were aimed at making life easier, more fun, and less time consuming. Some inventions satisfied more important needs, and contributed to great advances in the field of personal health. Many of these were inspired by necessity, and welcomed with open arms.
One invention of the 1920's was the Iron Lung. This machine was to be the most important advance in medicine at that time. Through extensive research and testing, Philip Drinker and Louise A. Shaw, at the Harvard School of Public Health, invented the Iron Lung (respirator) in 1927. If a person's lungs were not functioning properly, they could be placed in this metal tank. Once inside, a person's chest would expand and decrease due to air pressure changes within the tank. This air pressure change would actually force a body to breath without any help from the lungs, this was for only as long as the person remained inside of the tank. This machine offered .
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many lifesaving possibilities, and was of extreme benefit during the 1950's polio epidemic (Sproule, "Iron Lung"). Then in1928, Max Knoll and Ernst Ruska introduced the electron microscope (Rayburn, 1920s Timeline). Both were to be of great advantage to the world.