Patent ID: 7582873

Claim:
A method for detecting a type of anesthetic gas, comprising: generating a light with a plurality of wavelengths, the light comprising a plurality of light beams with central frequencies corresponding to the plurality of wavelengths; passing said light through a gas chamber, wherein the gas chamber is filled with said type of anesthetic gas, and said type of anesthetic gas has an absorption characteristic with respect to said plurality of light beams; detecting a light intensity of each of the plurality of light beams transmitted through the gas chamber to obtain a relative absorption coefficient between selected two of said plurality of light beams attenuated, wherein the plurality of light beams are absorbed by said type of anesthetic gas and are attenuated; and determining the type of anesthetic gas based on the relative absorption coefficient between the selected two of said plurality of attenuated light beams without determining or identifying a concentration of the anesthetic gas.