Experimental setup.

<p>The <i>bias flow experiments</i> (top) were performed to measure pressure stability and imposed WOB with in-line and flow-through position. A bias flow of 0 L/min is equivalent to in-line positioning. The <i>variable flow CPAP generator</i> experiments (bottom) were performed with an Infant Flow variable flow NCPAP generator. To simplify, the pressure recording tube on the Infant Flow was not included in the illustration.