function of an anesthesia machine is to prepare a gas mixture of precisely
known, but variable composition. The gas mixture can then be delivered to a
breathing system. Anesthesia machine itself has evolved from a simple pneumatic
device to a complex array of mechanical, electrical and computer – controlled
anesthesia machine consists of gas supply , gas control , breathing control ,
ventilation and scavenging.
We deal with many such machines for long time by breakdown and