The VECTOR et CPAP is intended for treating obstructive sleep apnea. Besides the CPAP mode, the device also provides the FLEXLINE mode. The pressure increase during inspiration and pressure decrease during expiration, which is proportional to the patient flow. To generate the necessary pressure, the device is provided with an electronically controlled blower. In order to keep the stress for the patient as low as possible, the blower has been designed with a high reserve capacity and a quick control response. The pressure is measured directly in the mask and constantly controlled by the device. Consequently, the breathing work for the patient is as easy as possible. In addition to the mask alarm, the device offers another safety function, the power failure alarm. It automatically restarts the motor after power restoration. A quartz alarm clock further adds to the comfort when using the device. Further comfort functions include a soft start ramp, the automatic start-stop function and the adjustable display brightness. While passing through the device, the air is heated a little, so that it has a higher water absorbency. When indoor air is dry in winter, the mucous membranes in mouth and nose may become particularly dry. For that reason, a therapy might require air humidification.