Figure 1
From: Pulmonary hemodynamic responses to in utero ventilation in very immature fetal sheep
The ventilation circuit (white tubes) was connected to the endotracheal tube via a "Y" piece. An additional catheter was inserted into the upper trachea (black tube) and directed toward the glottis. All catheters were exteriorized via a flank incision. The upper tracheal catheter was connected to the ventilation circuit creating an exteriorized 'tracheal loop' to allow normal flow of lung liquid.