Abstract: An analysis method determines a functional parameter of an organ by measuring 13CO2 content in exhaled air of an individual to which a substrate has been administered. The reaction of the substrate in the body of the individual enriches the exhaled air with 13CO2. The maximum reaction rate of the substrate in the body is determined via a change of the measured 13CO2 content in the exhaled air using zero-order enzyme kinetics. An aqueous methacetin solution having a pH greater than 7.0 is used in the analysis method. A face mask separates the exhaled air from inhaled air. The face mask is configured such that inhaled and exhaled air flows essentially completely through the face mask. Exhalation and inhalation valves in the face mask allow a flow of inhaled and exhaled air through the face mask. A diagnostic method is used to determine the functional parameters of the organ.

Abstract: An analysis method determines a functional parameter of an organ by measuring 13CO2 content in exhaled air of an individual to which a substrate has been administered. The reaction of the substrate in the body of the individual enriches the exhaled air with 13CO2. The maximum reaction rate of the substrate in the body is determined via a change of the measured 13CO2 content in the exhaled air using zero-order enzyme kinetics. An aqueous methacetin solution having a pH greater than 7.0 is used in the analysis method. A face mask separates the exhaled air from inhaled air. The face mask is configured such that inhaled and exhaled air flows essentially completely through the face mask. Exhalation and inhalation valves in the face mask allow a flow of inhaled and exhaled air through the face mask. A diagnostic method is used to determine the functional parameters of the organ.

Abstract: The invention relates to an analysis method for determining a functional parameter of an organ of a human or animal individual by measuring the 13CO2 content in the air exhaled by the individual to which a substrate has been administered the reaction of which in the body of the individual enriches the air exhaled by the individual with 13CO2. The method is characterized by using a measuring device, the maximum reaction rate of the substrate in the body of the individual being determined via a change of the measured 13CO2 content in the air exhaled by the individual using zero-order enzyme kinetics. The invention also relates to an aqueous methacetin solution for use in said analysis method, the pH of the solution being greater 7.0. The invention also relates to a face mask (1) for use in the inventive method for separating the exhaled air from the air inhaled by an individual. Said face mask comprises a face mask body (2) and an air cushion (3) encircling the face mask body.

Abstract: The invention relates to an apparatus for spectroscopically analysing a gas, said apparatus having at least one radiation source (1), at least one detection apparatus (12; 20), at least one sample chamber (13) and a system of optical elements (4; 5; 6; 7; 9; 10; 11; 18; 19) which is intended and set up to direct at least part (3b) of the radiation (3) emitted by the radiation source (1) through the sample chamber (13) onto the detection apparatus (20), wherein the sample chamber (13) is used to hold a gaseous sample which contains the gas to be analysed, and wherein the apparatus is configured in such a manner that the sample can continuously flow through the sample chamber (13), and means (16) are provided for the purpose of determining the pressure and/or the volume and/or the concentration of the sample in the sample chamber (13). The invention also relates to a corresponding method for spectroscopically analysing a gas.