Respiratory analyzer and method for measuring changes in concentration of a gas component of a breathing gas mixture

摘要

A method and apparatus for measuring changes in the concentration of a particular gas component of a breathing gas mixture after inhalation and exhalation by means of a degradable sensor. This is done by exposing, during inhalation, the sensor to a breathing gas mixture of known concentration to produce an inhalation output corresponding to the measured concentration of the gas component in the inhalation. From the known concentration of the gas component in the breathing gas mixture and the measured concentration in the inhalation output, a degradation parameter is determined representing the instantaneous degradation condition of the sensor. The sensor is exposed to the breathing gas mixture during exhalation to produce an exhalation output corresponding to the measured concentration of the gas component in the exhalation; the exhalation output of the sensor is modified according to the determined degradation parameter; and the change in concentration is computed from the modified exhalation output and the measured inhalation output.