Abstract: A ventilation device for artificial ventilation, having: —a ventilation gas source; —a ventilation line arrangement; —a pressure-changing assembly for changing the pressure of the ventilation gas flowing in the ventilation line arrangement; —a control device; —an evaluation device for processing sensor signals; and —an O2 sensor assembly for determining an O2 concentration value representing the oxygen concentration of the ventilation gas flowing in the ventilation line arrangement, wherein the O2 sensor assembly outputs O2 sensor signals, which contain information regarding the O2 concentration value, to the evaluation device, and wherein the evaluation device is designed to determine, on the basis of the O2 sensor signals, an O2 change value representing a change in the O2 concentration value and, if the O2 change value satisfies a predefined condition, to infer degradation of the O2 sensor assembly and to output a signal.

Abstract: A ventilation device for artificial ventilation, having: —a ventilation gas source; —a ventilation conducting assembly for conducting inspiratory ventilation gas from the ventilation gas source to a patient-side, proximal ventilation-gas outlet opening and for conducting expiratory ventilation gas away from a proximal ventilation-gas inlet opening; —a pressure-changing assembly for changing the pressure of the ventilation gas flowing in the ventilation conducting assembly; —a control device, which is designed to control the operation of the ventilation gas source and/or the operation of the pressure-changing assembly; —an evaluation device for processing sensor signals; and —an O2 sensor assembly for determining an O2 concentration value representing the oxygen concentration of the ventilation gas flowing in the ventilation conducting assembly, wherein the O2 sensor assembly outputs O2 sensor signals, which contain information regarding the O2 concentration value, to the evaluation device, and wherein the eva