Assessment of concentration of inhalational compounds in the brain

Abstract

This invention directs to a method of assessing the concentration of an inhalational compound in the brain of a subject. The method includes administering a gas containing the compound into a subject to fill the pulmonary functional residual capacity, which is defined as the remaining lung volume at the end of an unforced respiration. The method also includes measuring an inspired compound concentration (Ci′) and an expired compound concentration (Ce′) after having filled the functional residual capacity with the gas. Therefore, a mixed venous compound concentration (Cb′) can be assessed based on the formula Cb′=[Ci′(M−1)+Ce′]/M, in which M is an alveolar membrane factor for the compound; and a brain compound concentration (Cb) can be assessed based on the formula Cb=(Ce′+2Cb′)/3 or Cb=(Ce′+3Cb′)/4.

Dependencies are inferred from the claim text.