VECTOR et BILEVEL The device is a therapy device in the BILEVEL version for treating obstructive sleep apnea. Trigger device The respiration trigger detects the patients efforts to breath in and out and signals these efforts to the control device. A flow-based trigger is integrated which can be set separately for inspiration and expiration. While the pressure increases during inspiration it decreases during expiration. In connection with an optimum flank adjustment this results in a ventilation which is very comfortable for the patient and which gives the patient the impression as if the device is following the natural respiration without delay. 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. In addition to the mask alarm, the device offers another safety function, the power failure alarm. It automatically restarts the motor after power restoration. For added comfort an alarm clock is integrated in the device. Further comfort functions include a soft start ramp, the automatic start-stop function and the adjustable display brightness.