Patent ID: 7001339

Claim:
An article comprising a machine-readable medium that stores machine-executable instructions, the instructions causing a machine to: receive values representing the concentration of a compound administered in a gas into a subject to fill the pulmonary functional residual capacity, the values including an inspired compound concentration (C i′ ) and an expired compound concentration (C e′ ), wherein the inspired compound concentration (C i′ ) and the expired compound concentration (C e′ ) are obtained after having filled the functional residual capacity with the gas; and output a representation of a compound concentration in the brain (C b ), in which the representation of the compound concentration in the brain (C b ) is assessed by the formula C b =(C e′ +C b′ )/2, wherein C b′ =[C i′ (M−1)+C e′ ]/M, M being an alveolar membrane factor for the compound.