A manual resuscitator assembly configured to allow measurement of the carbon dioxide (C02) concentration in breathing gas of a person being ventilated, the assembly comprises: - a selective colorimetric C02 detector provided with a detector surface adapted to change color rapidly and reversibly with the concentration of C02, when exposed to C02, - a detector holding part adapted to receive said colorimetric detector and attach said detector, - a manual resuscitator including a bi-directional gas conduit between an expiratory part and an inspiratory part of a breathing circuit block of the resuscitator, wherein said gas conduit being configured such that a small predetermined fraction of the breathing gas enters said detector holding part and contacts said detector surface during ventilation, - a docking part for receiving and attaching a mobile unit, which comprises an image capturing means, a processing means and a display, wherein the docking part is configured to position said image capturing means in a fixed relation to said colorimetric detector, such that said image capturing means may capture an optical property of said detector surface, and wherein said processing means is adapted to execute an application program adapted to perform a measurement of C02 concentration changes in the breathing gas by identifying changes in the optical property of said detector surface captured by said image capturing means.L'invention concerne un ensemble réanimateur manuel configuré pour permettre la mesure de la concentration de dioxyde de carbone (CO2) du gaz respiratoire d'une personne ventilée, l'ensemble comprend : - un détecteur de CO2 colorimétrique sélectif comprenant une surface de détecteur conçue pour changer de couleur rapidement et de façon réversible avec la concentration de CO2 lorsqu'elle est exposée à du CO2, - une partie de retenue de détecteur conçue pour recevoir ledit détecteur colorimétrique et fixer ledit détecteur, - un réanimateur manuel comprenant
