Figure 5
From: On the cardiorespiratory coordination assessed by the photoplethysmography imaging technique
Time–frequency ridges in cardiac and respiratory activity scalograms. The cones of influence (white dashed line) show the time–frequency ridges (white curve) used for estimating the m:n ratio and optimising the coordination function. The m:n ratio is the ratio between the instantaneous frequency of heart activity (m) and respiratory frequency (n), and is used to optimise the coordination function. In selected scalograms, an increase in heart rate can be noticed during the CPT (14 to 15 min of the experiment). It is also possible to observe the change in respiratory rate just during the CPT phase.
