Method for detecting a gas of interest in air exhaled by a user

Abstract

A method for estimating the concentration of a gas of interest in the air exhaled by a user, the device comprising a sensor for the gas of interest, the method comprising: a) during an expiration, extending from an initial expiration time ( ), acquisition of a detection signal ( ), resulting from the gas sensor; b) during an inspiration, extending from an initial inhalation time ( ), acquisition of a detection signal ( ), resulting from the gas sensor, at different inhalation times; c) with the detection signals resulting from a), estimation of an expiration limit value towards which the expiration signals tend; d) with the detection signals resulting from b), estimation of an inhalation limit value ( ), towards which the inhalation signals tend; e) comparison of the expiration limit value resulting from step c), and the inhalation limit value resulting from step d);