3 Design and functional description
After selecting the first field, the observation time period can be set via
the "IGR" control knob in the levels 1, 6, 12, 24, 48 and 72 h. Pressing
the arrow key in the second window opens a dropdown menu. Here you
can select the required trend. Up to two trends can be displayed at the
same time for pressure, minute volume and frequency.
Tab. 11: Displayable trends