a respiratory event the actual pressure is already too low for the actual sleeping state of the patient the excessively low pressure should be raised as fast as possible so that the patient 39 s sleep is not disturbed by further respiratory events after the desired pressure has been raised in step 36 the desired pressure is compared with the value stored in the memory u201c oldpressure u201d in the memory u201c oldpressure u201d the desired pressure was stored in step 32 at the beginning of the ramp when the desired pressure differs from the pressure stored in the memory u201c oldpressure u201d by more than the tolerance in step 37 this is interpreted as an indication that the pressure at the beginning of the ramp was positioned near the optimum pressure for the actual sleeping state of the patient in this case the time stored in the memory u201c normaltime u201d is prolonged in step 38 so that the patient 39 s sleep is not unnecessarily disturbed by further respiratory events that are provoked by way of trial by reducing the desired pressure in step 33 the prolongation in step 38 can take place by addition of a constant value or by multiplication with a value greater than 1 following step 37 or 38 the desired pressure is kept constant at least for the time stored in the memory u201c normaltime u201d this condition is checked in step 41 while the desired pressure is being kept constant it is further checked in step 40 whether respiratory events occur if this is the case the desired pressure is further raised in step 36 after the actual time has been stored in the memory u201c starttime u201d in step 35 after it has been determined in step 41 that since.