Figure 1.

Flowchart presenting all the steps carried out to extract the respiratory pattern from video recorded with the built-in camera (on the left) and from the pressure-drop signal collected at the level of nostrils with the reference device (on the right). Region Of Interest (ROI) is the red rectangle; the area recorded by the camera is highlighted with the blue rectangle, the black point is the pixel (with coordinates $x_P$, $y_P$) at the level of the jugular notch.