Method and apparatus for determining a portion of a for the metabolic function of a living being in the topmost layer of characteristic constituent in the exhaled air from the living beings

摘要

The present invention relates to a method for determining a portion of a_{a, 1} a first, for the metabolic function of a living being in the topmost layer of characteristic constituent in the exhaled air from the living being, in particular of the proportion of carbon dioxide (co₂) or of oxygen (o₂), the exhaled air at least two components (i = 1, 2,...), each with a proportion of component a_{a, i} , and wherein the molecular weights m_i and the adiabatic coefficient k_i the components are known, characterized in that the sound-propagation velocity v_S in the exhaled air is measured, and in that the proportion of component a_{a, 1} of the first constituent in the exhaled air is calculated using the measured speed of sound v_S, the temperature t of the exhaled air and the relationship m_G/k_G = R x (t / v_S²), for the molecular weight m._G the exhaled air is true m_G = Sum of (a_{a, i} x m_i), i = 1, 2,.., and for the adiabatic coefficient k_G the exhaled air is 1 / (1 - k_G) = Sum of (a_{a, i}/(1 - k_i)), i = 1, 2,.., and r have the general gas constant, as well as a device for carrying out this process.