Mechanical Development of the Iron Lung
In 1926, the Consolidated Gas Company of New York used its Liability Insurance Fund to establish a committee to research resuscitation. As a business program, the executives responsible for the development of this committee intended to improve safety standards for the company's workers.
Among the medical scientists and engineers invited to sit on committee was Harvard University School of Public Health physiology professor Dr. Cecil K. Drinker. Drinker suggested that the committee consider supporting research by his brother, the chemical engineer Dr. Philip Drinker, and his colleague, Dr. Louis Agassiz Shaw, who were already working on artificial resuscitation at Harvard University. The committee agreed and sent a check for $5,000 in the fall of 1927 to support further investigation.9
Drinker and Shaw's research was focused upon the discovery of true artificial resuscitation. In their experimentation, they placed an anaesthetized cat in a sealed iron box with a neck collar, allowing the body to be within a fully-pressurized environment. Under these conditions, they were able to record accurate measurements of respiration as it was directly relative to their control of the air pressure within the sealed box. Inhalation increased the cat's volume within the box and made the pressure rise, while exhalation produced the opposite effect.
- Model of the Drinker and Shaw iron lung, tested on a cat.
The scientists hoped to arrive at true artificial resuscitation by testing a hypothesis: if the subject could not breathe independently, then increasing and decreasing the box's pressure would induce respiration.
In order to test this hypothesis, Drinker and Shaw injected the cat with the South American arrow-poison curare to produce an effect of extremely relaxed muscles, to the point of respiratory arrest. Drinker and Shaw then placed the cat into the sealed box and used a hand-operated piston to manually control the pressure. The experiment was successful and showed that controlled pressure in a sealed environment could induce respiration.10 Following this successful experiment, and with an additional $2,000 in funding from the Consolidated Gas, Drinker and Shaw extended their research to a larger device that could be tested on humans.11