Figure 7.

Sample motion models plotted over the range of binned respiratory positions. Models shown are from a wide range of respiratory patterns, including shallow breathing (V5), medium depth breathing (V1) and consistent deep breathing (V6). V8 illustrates a trained deep breath followed by tidal breathing. Shallow breathing shows highly linear motion in the Z_p direction and minimal X_p and Y_p translations, whereas deep breathing shows hysteresis in the Z_p direction and significant X_p and Y_p translations. Trained breathing in V8 shows improved characterization of inspiratory and expiratory curves, which could improve model accuracy in case of deep breathing during the acquisition.