Lewis Intratracheal Apparatus, 1931

Rights Managed

SS2802757

SW6929

Lewis Intratracheal Apparatus, an anesthetic machine from 1931. This is a modified version of the continuous flow anesthetic machine introduced in 1917 by Dr. Henry Boyle (1875-1941). It has the main elements which are still present in modern machines; providing an accurate and continuous supply of medical gases such as oxygen and nitrous oxide, mixed with an accurate concentration of anesthetic vapor (such as chloroform and ether), delivered to the patient at a safe pressure and flow. Anesthesia was delivered via a tube into the trachea (windpipe) of the patient. Gas flow meters and a pressure gauge are visible at the front of the apparatus.

SPL / Science Source