The iron-lung machine was one of the earliest life-saving machines. It was invented by Philip Drinker of Harvard, U.S.A in 1929. This device is meant to aid those who have difficulty in breathing, either due to a paralysis of chest muscles or due to some disease or an accident.
This machine has an air-tight chamber on wheels. The patient lies on a foam-rubber bed with an adjustable head and foot rests. It is operated by electricity, but has a safety device which gives a warning signal in the vent of power failure. The machine can then be operated by hand. It has a cover which can be opened to give access to the patient. The patient’s head is usually enclosed in a plastic dome.
The machine helps in breathing by alternately reducing and increasing the air pressure around the patient’s body. When the pressure is reduced, his chest expands and air comes into his lungs through the normal air passages, as his head remains outside the machine. When the pressure is increased, the chest contracts and air is automatically expelled from the lungs.
During a heart operation, a heart-lung machine is used. This takes over the function of the heart and lungs and the surgeon can perform the surgery safely. The technical name for this machine is the cardiopulmonary bypass machine, since it takes over the job of both heart and lungs. Blood returning along veins, from the body’s organs to the heart, is led out of the body along a tube to a gas exchange unit. Here carbon dioxide is removed from the blood and oxygen is added – thus doing the lung’s job. The blood then flows through a rotary pump which does the heart’s job and back into the main arteries. This is a very important device during heart surgery.
