A respiratory assist apparatus (100) comprising: a gas supply device adapted to provide gas at a substantially positive mean pressure； a humidifier (106) adapted to humidify said gas； characterized in that: said apparatus (100) is configurable to at least two configurations, a first configuration with an inoperative predetermined functionality and said operative gas supply device, and a second configuration with said predetermined functionality and said operative gas supply device , wherein the default functionality is active humidification, in the first configuration said humidifier (106) is inoperative and said gas supply device is operative, and in the second configuration said humidifier (106) is operative and said delivery device of gas is operative, said apparatus (100) is configured to the second configuration by installing an activation tool in said respiratory assistance apparatus (100), wherein said activation tool is a predetermined magnetic key and said apparatus (100) is configured to the second configuration by coupling said ma key predetermined genetics with said apparatus (100).Un aparato de asistencia respiratoria (100) que comprende: un dispositivo de suministro de gas adaptado para proporcionar gas a una presión media sustancialmente positiva； un humidificador (106) adaptado para humidificar dicho gas； caracterizado por que: dicho aparato (100) es configurable a al menos dos configuraciones, una primera configuración con una funcionalidad predeterminada inoperativa y dicho dispositivo de suministro de gas operativo, y una segunda configuración con dicha funcionalidad predeterminada y dicho dispositivo de suministro de gas operativos, en el que la funcionalidad predeterminada es humidificación activa, en la primera configuración dicho humidificador (106) es inoperativo y dicho dispositivo de suministro de gas es operativo, y en la segunda configuración dicho humidificador (106) es operativo y dicho dispositivo de suministro de gas es operativo, dic
