Research Article

Using Graph Theory to Assess the Interaction between Cerebral Function, Brain Hemodynamics, and Systemic Variables in Premature Infants

Figure 9

Comparing the vertex degree values (red) with the graph average degree (black) after administration of propofol at t = 0 minutes. The graph models were constructed using (a) and (b). The results are presented for the whole group of study (). From top to bottom, the vertex degree di is compared to the graph average degree for HR, MABP, SaO2, rScO2, and EEG, respectively. dMABP highly determines the signal interaction pattern during the first 30 minutes after propofol administration, while dEEG highly influences the signal interaction pattern from 30 minutes to 90 minutes after propofol administration. After 90 minutes, the neonates are recovered from propofol, as indicated by the steady reference levels observed after 90 minutes.
(a) Graphs constructed using
(b) Graphs constructed using