The heart-lung machine is an apparatus used to aid the body during an open-heart surgery in which the heart is non-functional. It is used as a substitute for the work the heart and lungs typically perform when the heart is functioning properly. As a substitute for the right atrium, the heart-lung machine contains a chamber that receives blood from the body.
The blood is then oxygenized by a machine that removes carbon dioxide and replaces it with oxygen, the task normally done by the lungs. Replacing the work of the left side of the heart, the pump then circulates freshly oxygenated blood back into the body. A network of tubes connects all of the facets of the heart-lung machine from and to the body. When surgery is complete, the machine is gradually used less and less until it is no longer necessary and the heart can depend on itself again.
Two types of pumps make up the heart-lung machine: a centrifugal pump and four roller pumps. The centrifugal pump is used for the circulation of the blood outside of the body. The roller pumps are used for transport of fluids and gas to and from the heart chambers and surgical area.