Lungs Diagram Biography
(Source google.com)
A negative pressure ventilator, often referred to
colloquially as an iron lung, is a form ofmedical ventilator that enables a
person to breathe when normal muscle control has been lost or the work of
breathing exceeds the person's ability. Examples of the device include both the
Drinker respirator and the Both respirator. The negative form of pressure
ventilation has been almost entirely superseded by positive pressure
ventilation or biphasic cuirass ventilation. Humans, like most other animals,
breathe by negative pressure breathing, the rib cage expands and the diaphragm
contracts, expanding the chest cavity. This causes the pressure in the chest
cavity to decrease, and the lungs expand to fill the space. This, in turn,
causes the pressure of the air inside the lungs to decrease (it becomes
negative, relative to the atmosphere), and air flows into the lungs from the
atmosphere: inhalation. When the diaphragm relaxes, the reverse happens and the
person exhales. If a person loses part or all of the ability to control the
muscles involved, breathing becomes difficult or impossible.
The person using the iron lung is placed into the central
chamber, a cylindrical steel drum. A door allowing the head and neck to remain
free is then closed, forming a sealed, air-tight compartment enclosing the rest
of the person's body. Pumps that control airflow periodically decrease and
increase the air pressure within the chamber, and particularly, on the chest.
When the pressure is below that within the lungs, the lungs expand and
atmospheric pressure pushes air from outside the chamber in via the person's
nose and airways to keep the lungs filled; when the pressure goes above that
within the lungs, the reverse occurs, and air is expelled. In this manner, the
iron lung mimics the physiological action of breathing: by periodically
altering intrathoracic pressure, it causes air to flow in and out of the lungs.
The iron lung is a form of non-invasive therapy.
In 1670, English scientist John Mayow came up with the idea
of external negative pressure ventilation. Mayow built a model consisting of
bellows and a bladder to pull in and expel air. The first negative pressure
ventilator was described by Scottish physician John Dalzielin 1832. Successful
use of similar devices was described a few years later. Early prototypes
included a hand-operated bellows-driven "Spirophore" designed by Dr.
Woillez of Paris (1876), and an airtight wooden
box designed specifically for the treatment of polio by Dr. Stueart of South Africa
(1918). Stueart's box was sealed at the waist and shoulders with clay and
powered by a motor-driven bellows. The first of these devices to be widely used
however was developed by Drinker and Shaw in 1928. The iron lung, often
referred to in the early days as the "Drinker respirator", was
invented by Philip Drinker (1894–1972) and Louis Agassiz Shaw, Jr., professors
of industrial hygiene at the Harvard School of Public Health. The machine was
powered by an electric motor with air pumps from two vacuum cleaners. The air
pumps changed the pressure inside a rectangular, airtight metal box, pulling
air in and out of the lungs. The first clinical use of the Drinker respirator
on a human was on October 12, 1928, at theBoston Children's Hospital. The
subject was an eight-year-old girl who was nearly dead as a result of
respiratory failure due topoliomyelitis (often called polio or infantile
paralysis). Her dramatic recovery, within less than a minute of being placed in
the chamber, helped popularize the new device. Boston manufacturer Warren E. Collins began
production of the iron lung that year. Although it was initially developed for
the treatment of victims of coal gas poisoning, it was most famously used in
the mid-20th century for the treatment of respiratory failure caused by poliomyelitis.
Danish physiologist August Krogh, upon returning to Copenhagen in 1931 from a visit to New York where he saw the Drinker machine in
use, constructed the first Danish respirator designed for clinical purposes.
Krogh's device differed from Drinker's in that its motor was powered by water
from the city pipelines. Krogh also made an infant respirator version.
In 1931, John Haven Emerson (February 5, 1906 – February 4,
1997) introduced an improved and less expensive iron lung The Emerson iron lung
had a bed that could slide in and out of the cylinder as needed, and the tank
had portal windows which allowed attendants to reach in and adjust limbs,
sheets, or hot packs.[ Drinker and
Harvard University sued Emerson, claiming he had infringed on patent rights.
Emerson defended himself by making the case that such lifesaving devices should
be freely available to all.] Emerson also demonstrated that every aspect of
Drinker's patents had been published or used by others at earlier times. Since
an invention must be novel to be patentable, prior publication/use of the
invention meant it was not novel and therefore unpatentable. Emerson won the
case, and Drinker's patents were declared invalid.
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Lungs Diagram Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee
Lungs Diagram Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee
Lungs Diagram Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee
Lungs Diagram Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee
Lungs Diagram Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee
Lungs Diagram Lungs Diagram of a Smoker after Smoking Cancer Anatomy And Heart Drawing Images AFter Smoking Wee
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