Figure 4From: Diaphragm ultrasound as indicator of respiratory effort in critically ill patients undergoing assisted mechanical ventilation: a pilot clinical study Correlation between thickening fraction and esophageal and diaphragmatic pressure-time product. PTPes, esophageal pressure-time product per breath; PTPdi, diaphragmatic pressure-time product per breath; TF, thickening fraction; PSV, pressure support ventilation.Back to article page